Background of Invention
Field of the Invention
[0001] The present invention relates generally to aqueous dispersions and dispersion compounds.
Background Art
[0002] Long fiber-reinforced thermoplastic resins have been widely used for various industrial
product components because they possess excellent mechanical strength, heat resistance,
and formability. While it is difficult to produce a long fiber-reinforced thermoplastic
resin by kneading cut fibers with a thermoplastic resin in an extruder, it is known
that long fiber-reinforced thermoplastic resins can be made from long fiber-reinforced
thermoplastic concentrates.
[0003] Long fiber-reinforced thermoplastic concentrates are known to be produced by melt
pultrusion processes. In melt pultrusion, a fiber strand is pulled through a thermoplastic
melt and becomes wetted with the molten matrix polymer or carrier resin. Post forming
or stripping means are used to set a consistent fiber content.
[0004] However, fiber levels typically do not exceed between 50 to 70 weight percent of
the weight of the concentrate. Owing to the high viscosity of thermoplastic melts,
incomplete penetration of the fiber with resin may occur during pultrusion. To achieve
adequate penetration of the fiber strand by the melt, pultrusion processes generally
use very low molecular weight thermoplastics as the carrier resin. However, even low
levels of low molecular weight thermoplastic carrier resins present in a long fiber-reinforced
thermoplastic concentrate can have deleterious effects on the mechanical strength,
heat resistance, and formability of the non-reinforced thermoplastic resin to which
the concentrate is added.
[0005] In processes described in
U.S. Patent Nos. 4,626,306,
4,680,224,
5,725,710,
5,888,580, and
6,045,912, a liquid polymer powder dispersion is used for impregnating the fiber strand. The
thermoplastic powder, typically a low molecular weight thermoplastic, is applied to
the fiber strand moving in a longitudinal direction through the powder dispersion;
the dispersing medium, a solvent (preferably water), is removed from the strand, for
example, by heating, after which the thermoplastic is melted, and the composite is
consolidated, for example, by rolling.
[0006] In these processes, the deposition of constant quantities of powder on the fiber
strand moving through the dispersion bath may present problems. The polymer content
of the composite depends on the solids content of the dispersion bath. The concentration
in the immediate vicinity of the strand fluctuates and does not always correspond
precisely to the average concentration of the subsequently supplied dispersion. Numerous
remedies have been proposed, such as guides, strand measuring calibration devices,
concentration control of the liquid polymer powder dispersion bath, etc., which do
not address some of the concerns.
[0007] Alternatively, aqueous dispersions of thermoplastic resins have been produced by
a process wherein a polymerizable monomer, which is the resin raw material, is polymerized
by emulsion polymerization in an aqueous medium in the presence of an emulsifying
agent. Advantageously, emulsion polymerizations may produce high molecular weight
thermoplastic resins. However, this process is limited by the few number of polymerizable
monomers that can be used, therefore, the number of aqueous dispersions of thermoplastic
resins that can be produced is limited.
[0008] Glass fibers, including continuous fibers, strands and rovings and chopped fibers
and strands, have also been used to reinforce various polymeric matrices and have
been useful in reinforcing polyolefins. The glass fibers are typically treated during
their formation with a chemical treating composition, usually referred to as a sizing
composition, to protect the fibers in subsequent processing and to assist the fibers
in adhering to a polymeric matrix.
[0009] U.S. Patent No. 4,728,573 discloses chemically treated glass fibers prepared by attenuating glass fibers from
molten streams of glass issuing forth from the orifices in a bushing or similar device,
treating the glass fibers with an aqueous chemical treating composition, gathering
the fibers into one or more strands, and collecting the strands as chopped strands
or continuous strands in a multilayered package. The aqueous chemical treating composition
includes one or more amine organo coupling agents, an aqueous emulsion or dispersion
of a carboxylic-modified polyolefin resin that has been neutralized or nearly neutralized
with an organic or inorganic base, an aqueous-soluble, dispersible or emulsifiable
film-forming polymer, and a binder stabilizer.
[0010] WO2004099529 discloses a drywall tape including a web of glass fibers and a coating disposed over
a portion of the glass fibers. The coating comprises a resinous binder that is at
least partially soluble or dispersible in a joint compound. The coating is further
capable of forming an adhesive bond with the joint compound when set.
[0011] U.S. Patent No. 6,818,698 (
WO2004031246) discloses the application of high molecular weight functionalized polyolefin emulsions
onto glass fibers, either during the glass fiber manufacturing process or at a later
stage, to obtain reinforced polypropylene composites with a high mechanical performance.
[0012] The polyolefin dispersions used in the patents and publications noted above each
contain functionalized polyolefins, such as maleic anhydride grafted polypropylene.
Other publications that disclose coating glass fibers or glass-fiber reinforced articles
include
U.S. Patent Nos. 5,437,928,
5,891,284, and
5,972,166.
[0013] It is desired to improve these and other fiber-based reinforcement structures. Improvements
needed may include adhesion between the fiber-based reinforcement and additional components
of a structure. In addition, enhancements to the ability to form articles using the
reinforced structure may be desirable.
Summary of Invention
[0014] In one aspect, embodiments disclosed herein relate to a method of forming an article,
the method may include applying a compound to a glass-containing substrate, the compound
may include an aqueous dispersion that may include: (a) a thermoplastic resin; (b)
a dispersion stabilizing agent; and (c) water; and removing at least a portion of
the water
[0015] In other aspects, embodiments disclosed herein relate to an article including: a
compound in contact with a portion of a glass-containing substrate, wherein the compound
at the time of contacting may include an aqueous dispersion that may include (a) a
polyolefin having a deformation temperature of less than 110°C, (b) a dispersion stabilizing
agent, and (c) water, wherein the compound imparts a modified property to the substrate,
and wherein the substrate is formable.
[0016] In other aspects, embodiments disclosed herein relate to an article formed from a
compound in contact with a portion of a glass-containing substrate, wherein the compound
at the time of contacting may include an aqueous dispersion that may include: (a)
a thermoplastic resin; (b) a dispersion stabilizing agent; and (c) water wherein the
article is at least 92 percent by weight glass based on a total weight of the glass-containing
substrate, the thermoplastic resin, and the dispersion stabilizing agent.
[0017] In other aspects, embodiments disclosed herein relate to a coated fiber that may
include: a compound in contact with a portion of a glass-based fiber, wherein the
compound at the time of contacting may include an aqueous dispersion formed from:
(a) a thermoplastic resin; (b) a dispersion stabilizing agent; and (c) water, wherein
the fiber has a diameter between 5 and 35 microns; and wherein a thickness of a coating
layer of the compound on the glass-based fiber ranges from about 0.1 to 10 microns.
[0018] In other aspects, embodiments disclosed herein relate to a method of coating a fiber
including: applying a compound to a glass-based fiber, the compound may include: an
aqueous dispersion including: (a) a thermoplastic resin; (b) a dispersion stabilizing
agent; and (c) water; removing at least a portion of the water.
[0019] In other aspects, embodiments disclosed herein relate to an article having: at least
one layer of a compound disposed on at least a portion of a glass-containing substrate,
wherein the compound may include: (a) a polyolefin having a deformation temperature
of less than 110°C; and (b) a dispersion stabilizing agent; wherein the compound imparts
a modified property to the substrate; and wherein the substrate is formable.
[0020] Other aspects and advantages of the invention will be apparent from the following
description and the appended claims.
Brief Description of Drawings
[0021] Figure 1 shows an extruder that may be used to form dispersions in accordance with
embodiments disclosed herein.
[0022] Figure 2 is a block flow diagram showing an apparatus suitable for practicing the
process of the present invention.
[0023] Figure 3 is a block flow diagram showing an alternative apparatus suitable for practicing
the process of the present invention.
Detailed Description
[0024] Embodiments relate to articles manufactured by coating or impregnating a structure
with a compound. In some embodiments, the compound, when applied, may include a dispersion
that includes a base polymer and a stabilizing agent. In certain embodiments, the
structure may be a glass-based fiber. In other embodiments, the structure may be a
glass-containing substrate.
[0025] Other embodiments relate to fiber-reinforced articles manufactured using an aqueous
dispersion of polyolefins. For example, aqueous dispersion of polyolefins may be used
to coat fiber-based structures (including fiber rovings, mats and fabrics). In certain
embodiments, the polyolefin dispersions may contain at least one polyolefin phase
that has no functionality, thereby producing a coating/binder having an unfunctionalized
polyolefin phase. Inclusion of this unfunctionalized polyolefin in a coating/binder
may result in improved properties, such as improved binding and compatibility with
other components in a structure.
[0026] As used herein, the term "glass-based fiber" refers to glass fibers and natural or
synthetic fibers that contain at least 50% glass.
[0027] As used herein, the term "glass-containing substrate" refers to at least a two-dimensional
structure containing glass that is not a mono-filament or a bundle of mono-filaments.
Accordingly, the glass-containing substrate has both a length and a width, and in
preferred embodiments is formable.
[0028] As used herein, the term "formable" refers to the ability to further process a substrate
into a new shape under application of heat and/or pressure.
[0029] Aqueous Dispersion
[0030] More generally, embodiments disclosed herein relate to aqueous dispersions and compounds
made from aqueous dispersions that are useful for imparting a modified property to
a substrate, such as a glass-based fiber or a glass-containing substrate. In certain
embodiments, the dispersions may be contacted with the substrate in the form of a
froth or a foam. Dispersions used in embodiments disclosed herein include water, (A)
at least one thermoplastic resin, and (B) a dispersion stabilizing agent. These are
discussed in more detail below.
Thermoplastic resin
[0031] The thermoplastic resin (A) included in embodiments of the aqueous dispersion of
the present disclosure is a resin that is not readily dispersible in water by itself.
The term "resin," as used herein, should be construed to include synthetic polymers
or chemically modified natural resins.
[0032] Resins used in embodiments disclosed herein may include elastomers and blends of
olefin polymers. In some embodiments, the thermoplastic resin is a semicrystalline
resin. The term "semi-crystalline" is intended to identify those resins that possess
at least one endotherm when subjected to standard differential scanning calorimetry
(DSC) evaluation. Some semi-crystalline polymers exhibit a DSC endotherm that exhibits
a relatively gentle slope as the scanning temperature is increased past the final
endotherm maximum. This reflects a polymer of broad melting range rather than a polymer
having what is generally considered to be a sharp melting point. Some polymers useful
in the dispersions have a single melting point while other polymers have more than
one melting point.
[0033] In some polymers one or more of the melting points may be sharp such that all or
a portion of the polymer melts over a fairly narrow temperature range, such as a few
degrees centigrade. In other embodiments, the polymer may exhibit broad melting characteristics
over a range of about 20°C. In yet other embodiments, the polymer may exhibit broad
melting characteristics over a range of greater than 50°C.
[0034] The thermoplastic resin may be a non-functionalized resin in some embodiments. In
other embodiments, the thermoplastic resin may be a non-polar resin.
[0035] Examples of the thermoplastic resin (A) which may be used in embodiments disclosed
herein include homopolymers and copolymers (including elastomers) of an alpha-olefin
such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-
pentene, 1-heptene, 1-hexene, 1-octene, 1-decene, and 1-dodecene, as typically represented
by polyethylene, polypropylene, poly-1-butene, poly-3-methyl-1-butene, poly-3-methyl-1-pentene,
poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer,
and propylene- 1-butene copolymer; copolymers (including elastomers) of an alpha-olefin
with a conjugated or non-conjugated diene, as typically represented by ethylene-butadiene
copolymer and ethylene-ethylidene norbornene copolymer; and polyolefins (including
elastomers) such as copolymers of two or more alpha-olefins with a conjugated or non-conjugated
diene, as typically represented by ethylene-propylene-butadiene copolymer, ethylene-propylene-
dicyclopentadiene copolymer, ethylene-propylene-1,5-hexadiene copolymer, and ethylene-propylene-ethylidene
norbornene copolymer; ethylene-vinyl compound copolymers such as ethylene-vinyl acetate
copolymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl chloride copolymer, ethylene
acrylic acid or ethylene-(meth)acrylic acid copolymers, and ethylene-(meth)acrylate
copolymer; styrenic copolymers (including elastomers) such as polystyrene, ABS, acrylonitrile-styrene
copolymer, α-methylstyrene-styrene copolymer, styrene vinyl alcohol, styrene acrylates
such as styrene methylacrylate, styrene butyl acrylate, styrene butyl methacrylate,
and styrene butadienes and crosslinked styrene polymers; and styrene block copolymers
(including elastomers) such as styrene-butadiene copolymer and hydrate thereof, and
styrene-isoprene-styrene triblock copolymer; polyvinyl compounds such as polyvinyl
chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer, polymethyl
acrylate, and polymethyl methacrylate; polyamides such as nylon 6, nylon 6,6, and
nylon 12; thermoplastic polyesters such as polyethylene terephthalate and polybutylene
terephthalate; polycarbonate, polyphenylene oxide, and the like; and glassy hydrocarbon-based
resins, including poly-dicyclopentadiene polymers and related polymers (copolymers,
terpolymers); saturated mono-olefins such as vinyl acetate, vinyl propionate and vinyl
butyrate and the like; vinyl esters such as esters of monocarboxylic acids, including
methyl acrylate, ethyl acrylate, n-butylacrylate, isobutyl acrylate, dodecyl acrylate,
n-octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl
methacrylate and the like; acrylonitrile, methacrylonitrile, acrylamide, mixtures
thereof; resins produced by ring opening metathesis and cross metathesis polymerization
and the like. These resins may be used either alone or in combinations of two or more.
Examples of specific thermoplastic resins include styrene butadiene copolymers with
a styrene content of from about 70 to about 95 weight percent.
[0036] As one suitable type of resin, the esterification products of a di-or polycarboxylic
acid and a diol comprising a diphenol may be used. These resins are illustrated in
U.S. Pat. No. 3,590,000, which is incorporated herein by reference. Other specific example of resins include
styrene/methacrylate copolymers, and styrene/butadiene copolymers; suspension polymerized
styrene butadienes; polyester resins obtained from the reaction of bisphenol A and
propylene oxide followed by the reaction of the resulting product with fumaric acid;
and branched polyester resins resulting from the reaction of dimethylterphthalate,
1,3-butanediol, 1,2-propanediol, and pentaerythritol, styrene acrylates, and mixtures
thereof.
[0037] Further, specific embodiments employ ethylene-based polymers, propylene-based polymers,
propylene-ethylene copolymers, and styrenic copolymers as one component of a composition.
Other embodiments use polyester resins, including those containing aliphatic diols
such as UNOXOL 3,4 diol available from The Dow Chemical Company (Midland, MI).
[0038] In selected embodiments, one component is formed from ethylene-alpha olefin copolymers
or propylene-alpha olefin copolymers. In particular, in select embodiments, the thermoplastic
resin comprises one or more non-polar polyolefins.
[0039] In specific embodiments, polyolefins such as polypropylene, polyethylene, copolymers
thereof, and blends thereof, as well as ethylene-propylene-diene terpolymers, may
be used. In some embodiments, preferred olefinic polymers include homogeneous polymers,
as described in
U.S. Pat. No. 3,645,992 issued to Elston; high density polyethylene (HDPE), as described in
U.S. Pat. No. 4,076,698 issued to Anderson; heterogeneously branched linear low density polyethylene (LLDPE); heterogeneously
branched ultra low linear density polyethylene (ULDPE); homogeneously branched, linear
ethylene/alpha-olefin copolymers; homogeneously branched, substantially linear ethylene/alpha-olefin
polymers, which can be prepared, for example, by processes disclosed in
U.S. Pat. Nos. 5,272,236 and
5,278,272, the disclosures of which are incorporated herein by reference; and high pressure,
free radical polymerized ethylene polymers and copolymers such as low density polyethylene
(LDPE) or ethylene vinyl acetate polymers (EVA).
[0040] Polymer compositions, and blends thereof, described in
U.S. Pat. Nos. 6,566,446,
6,538,070,
6,448,341,
6,316,549,
6,111,023,
5,869,575,
5,844,045, or
5,677,383, each of which is incorporated herein by reference in its entirety, may also be suitable
in some embodiments. In some embodiments, the blends may include two different Ziegler-Natta
polymers. In other embodiments, the blends may include blends of a Ziegler-Natta and
a metallocene polymer. In still other embodiments, the polymer used herein may be
a blend of two different metallocene polymers. In other embodiments, single site catalyst
polymers may be used.
[0041] In some embodiments, the polymer is a propylene-based copolymer or interpolymer.
In some particular embodiments, the propylene-based copolymer or interpolymer is characterized
as having substantially isotactic propylene sequences. The term "substantially isotactic
propylene sequences" and similar terms mean that the sequences have an isotactic triad
(mm) measured by
13C NMR of greater than about 0.85 in one embodiment; greater than about 0.90 in another
embodiment; greater than about 0.92 in another embodiment; and greater than about
0.93 in yet another embodiment. Isotactic triads are well-known in the art and are
described in, for example,
U.S. Pat. No. 5,504,172 and
WO 00/01745, which refer to the isotactic sequence in terms of a triad unit in the copolymer
molecular chain determined by
13C NMR spectra.
[0042] One embodiment of the propylene-based polymer is a propylene-ethylene copolymer or
interpolymer, where ethylene may be present in an amount from about 5% to about 25%
by weight. In some embodiment, the propylene-rich alpha-olefin interpolymer is characterized
as having an isotactic triad (mm) measured by
13C NMR of greater than about 0.85. Some such propylene-rich alpha-olefin interpolymers
may have from 5 to 25% by weight of ethylene-derived units and 95 to 75% by weight
of propylene-derived units. Additionally, some propylene-rich alpha-olefin interpolymers
have (a) a melting point of less than 90°C; (b) a relationship of elasticity to 500%
tensile modulus such that the elasticity is less than or equal to 0.935M+12, where
elasticity is in percent and M is the 500% tensile modulus in MPa; and (c) a relationship
of flexural modulus to 500% tensile modulus such that flexural modulus is less than
or equal to 4.2e
0.27M +50, where flexural modulus is in MPa and M is the 500% tensile modulus in MPa. In
some embodiments, the propylene rich alpha-olefin interpolymer comprises 6 to 20%
by weight of ethylene-derived units and 94 to 80% by weight of propylene-derived units.
In other embodiments, polymers may comprise 8 to 20% by weight of ethylene-derived
units and 92 to 80% by weight of propylene-derived units. In still other embodiments,
polymers may comprise 10 to 20% by weight of ethylene-derived units and 90 to 80%
by weight of propylene-derived units.
[0043] In other particular embodiments, the base polymer may be ethylene vinyl acetate (EVA)
based polymers. In other embodiments, the base polymer may be ethylene-methyl acrylate
(EMA) based polymers. In other particular embodiments, the ethylene-alpha olefin copolymer
may be ethylene-butene, ethylene-hexene, or ethylene-octene copolymers or interpolymers.
In other particular embodiments, the propylene-alpha olefin copolymer may be a propylene-ethylene
or a propylene-ethylene-butene copolymer or interpolymer.
[0044] In one particular embodiment, the thermoplastic resin may comprise an alpha-olefin
interpolymer of ethylene with a comonomer comprising an alkene, such as 1-octene.
The ethylene and octene copolymer may be present alone or in combination with another
thermoplastic resin, such as ethylene-acrylic acid copolymer. When present together,
the weight ratio between the ethylene and octene copolymer and the ethylene-acrylic
acid copolymer may range from about 1:10 to about 10:1, such as from about 3:2 to
about 2:3. The polymeric resin, such as the ethylene-octene copolymer, may have a
crystallinity of less than about 50%, such as less than about 25%. In some embodiments,
the crystallinity of the polymer may range from 5 to 35 percent. In other embodiments,
the crystallinity may range from 7 to 20 percent.
[0045] Embodiments disclosed herein may also include a polymeric component that may include
at least one multi-block olefin interpolymer. Suitable multi-block olefin interpolymers
may include those described in
U.S. Provisional Patent Application No. 60/818,911, for example. The term "multi-block copolymer" or refers to a polymer comprising
two or more chemically distinct regions or segments (referred to as "bocks") preferably
joined in a linear manner, that is, a polymer comprising chemically differentiated
units which are joined end-to-end with respect to polymerized ethylenic functionality,
rather than in pendent or grafted fashion. In certain embodiments, the blocks differ
in the amount or type of comonomer incorporated therein, the density, the amount of
crystallinity, the crystallite size attributable to a polymer of such composition,
the type or degree of tacticity (isotactic or syndiotactic), regio-regularity or regio-irregularity,
the amount of branching, including long chain branching or hyper-branching, the homogeneity,
or any other chemical or physical property.
[0046] The multi-block copolymers are characterized by unique distributions of polydispersity
index (PDI or M
w/M
n), block length distribution, and/or block number distribution due to the unique process
making of the copolymers. More specifically, when produced in a continuous process,
embodiments of the polymers may possess a PDI ranging from about 1.7 to about 8; from
about 1.7 to about 3.5 in other embodiments; from about 1.7 to about 2.5 in other
embodiments; and from about 1.8 to about 2.5 or from about 1.8 to about 2.1 in yet
other embodiments. When produced in a batch or semi-batch process, embodiments of
the polymers may possess a PDI ranging from about 1.0 to about 2.9; from about 1.3
to about 2.5 in other embodiments; from about 1.4 to about 2.0 in other embodiments;
and from about 1.4 to about 1.8 in yet other embodiments.
[0047] One example of the multi-block olefin interpolymer is an ethylene/α-olefin block
interpolymer. Another example of the multi-block olefin interpolymer is a propylene/α-olefin
interpolymer. The following description focuses on the interpolymer as having ethylene
as the majority monomer, but applies in a similar fashion to propylene-based multi-block
interpolymers with regard to general polymer characteristics.
[0048] The ethylene/α-olefin multi-block copolymers may comprise ethylene and one or more
co-polymerizable α-olefin comonomers in polymerized form, characterized by multiple
(i.e., two or more) blocks or segments of two or more polymerized monomer units differing
in chemical or physical properties (block interpolymer). In some embodiments, the
copolymer is a multi-block interpolymer. In some embodiments, the multi-block interpolymer
may be represented by the following formula:
(AB)
n
where n is at least 1, and in various embodiments n is an integer greater than 1,
such as 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, or higher; "A" represents
a hard block or segment; and "B" represents a soft block or segment. Preferably, A's
and B's are linked in a linear fashion, not in a branched or a star fashion. "Hard"
segments refer to blocks of polymerized units in which ethylene is present in an amount
greater than 95 weight percent in some embodiments, and in other embodiments greater
than 98 weight percent. In other words, the comonomer content in the hard segments
is less than 5 weight percent in some embodiments, and in other embodiments, less
than 2 weight percent of the total weight of the hard segments. In some embodiments,
the hard segments comprise all or substantially all ethylene. "Soft" segments, on
the other hand, refer to blocks of polymerized units in which the comonomer content
is greater than 5 weight percent of the total weight of the soft segments in some
embodiments, greater than 8 weight percent, greater than 10 weight percent, or greater
than 15 weight percent in various other embodiments. In some embodiments, the comonomer
content in the soft segments may be greater than 20 weight percent, greater than 25
weight percent, greater than 30 weight percent, greater than 35 weight percent, greater
than 40 weight percent, greater than 45 weight percent, greater than 50 weight percent,
or greater than 60 weight percent in various other embodiments.
[0049] In some embodiments, A blocks and B blocks are randomly distributed along the polymer
chain. In other words, the block copolymers do not have a structure like:
AAA—AA-BBB—BB
[0050] In other embodiments, the block copolymers do not have a third block. In still other
embodiments, neither block A nor block B comprises two or more segments (or sub-blocks),
such as a tip segment.
[0051] The multi-block interpolymers may be characterized by an average block index, ABI,
ranging from greater than zero to about 1.0 and a molecular weight distribution, M
w/M
n, greater than about 1.3. The average block index, ABI, is the weight average of the
block index ("BI") for each of the polymer fractions obtained in preparative TREF
from 20°C and 110°C, with an increment of 5°C:

where BI
i is the block index for the i
th fraction of the multi-block interpolymer obtained in preparative TREF, and w
i is the weight percentage of the i
th fraction.
[0052] Similarly, the square root of the second moment about the mean, hereinafter referred
to as the second moment weight average block index, may be defined as follows:

[0053] For each polymer fraction, BI is defined by one of the two following equations (both
of which give the same BI value):

where T
X is the analytical temperature rising elution fractionation (ATREF) elution temperature
for the i
th fraction (preferably expressed in Kelvin), P
X is the ethylene mole fraction for the i
th fraction, which may be measured by NMR or IR as described below. P
AB is the ethylene mole fraction of the whole ethylene/α-olefin interpolymer (before
fractionation), which also may be measured by NMR or IR. T
A and P
A are the ATREF elution temperature and the ethylene mole fraction for pure "hard segments"
(which refer to the crystalline segments of the interpolymer). As an approximation
or for polymers where the "hard segment" composition is unknown, the T
A and P
A values are set to those for high density polyethylene homopolymer.
[0054] T
AB is the ATREF elution temperature for a random copolymer of the same composition (having
an ethylene mole fraction of P
AB) and molecular weight as the multi-block interpolymer. T
AB may be calculated from the mole fraction of ethylene (measured by NMR) using the
following equation:

where a and β are two constants which may be determined by a calibration using a
number of well characterized preparative TREF fractions of a broad composition random
copolymer and/or well characterized random ethylene copolymers with narrow composition.
It should be noted that α and β may vary from instrument to instrument. Moreover,
one would need to create an appropriate calibration curve with the polymer composition
of interest, using appropriate molecular weight ranges and comonomer type for the
preparative TREF fractions and/or random copolymers used to create the calibration.
There is a slight molecular weight effect. If the calibration curve is obtained from
similar molecular weight ranges, such effect would be essentially negligible. In some
embodiments, random ethylene copolymers and/or preparative TREF fractions of random
copolymers satisfy the following relationship:

[0055] The above calibration equation relates the mole fraction of ethylene, P, to the analytical
TREF elution temperature, T
ATREF, for narrow composition random copolymers and/or preparative TREF fractions of broad
composition random copolymers. T
XO is the ATREF temperature for a random copolymer of the same composition and having
an ethylene mole fraction of P
X. T
XO may be calculated from LnP
X = α/T
XO + β. Conversely, Pxo is the ethylene mole fraction for a random copolymer of the
same composition and having an ATREF temperature of T
X, which may be calculated from Ln Pxo = α/T
X + β.
[0056] Once the block index (BI) for each preparative TREF fraction is obtained, the weight
average block index, ABI, for the whole polymer may be calculated. In some embodiments,
ABI is greater than zero but less than about 0.4 or from about 0.1 to about 0.3. In
other embodiments, ABI is greater than about 0.4 and up to about 1.0. In yet other
embodiments, ABI should be in the range of from about 0.4 to about 0.7, from about
0.5 to about 0.7, or from about 0.6 to about 0.9. In some embodiments, ABI is in the
range of from about 0.3 to about 0.9, from about 0.3 to about 0.8, or from about 0.3
to about 0.7, from about 0.3 to about 0.6, from about 0.3 to about 0.5, or from about
0.3 to about 0.4. In other embodiments, ABI is in the range of from about 0.4 to about
1.0, from about 0.5 to about 1.0, or from about 0.6 to about 1.0, from about 0.7 to
about 1.0, from about 0.8 to about 1.0, or from about 0.9 to about 1.0.
[0057] Another characteristic of the multi-block interpolymer is that the interpolymer may
comprise at least one polymer fraction which may be obtained by preparative TREF,
wherein the fraction has a block index greater than about 0.1 and up to about 1.0
and the polymer having a molecular weight distribution, M
w/M
n, greater than about 1.3. In some embodiments, the polymer fraction has a block index
greater than about 0.6 and up to about 1.0, greater than about 0.7 and up to about
1.0, greater than about 0.8 and up to about 1.0, or greater than about 0.9 and up
to about 1.0. In other embodiments, the polymer fraction has a block index greater
than about 0.1 and up to about 1.0, greater than about 0.2 and up to about 1.0, greater
than about 0.3 and up to about 1.0, greater than about 0.4 and up to about 1.0, or
greater than about 0.4 and up to about 1.0. In still other embodiments, the polymer
fraction has a block index greater than about 0.1 and up to about 0.5, greater than
about 0.2 and up to about 0.5, greater than about 0.3 and up to about 0.5, or greater
than about 0.4 and up to about 0.5. In yet other embodiments, the polymer fraction
has a block index greater than about 0.2 and up to about 0.9, greater than about 0.3
and up to about 0.8, greater than about 0.4 and up to about 0.7, or greater than about
0.5 and up to about 0.6.
[0058] Ethylene α-olefin multi-block interpolymers used in embodiments disclosed herein
may be interpolymers of ethylene with at least one C
3-C
20 α-olefin. The interpolymers may further comprise C
4-C
18 diolefin and/or alkenylbenzene. Suitable unsaturated comonomers useful for polymerizing
with ethylene include, for example, ethylenically unsaturated monomers, conjugated
or non-conjugated dienes, polyenes, alkenylbenzenes, etc. Examples of such comonomers
include C
3-C
20 α-olefins such as propylene, isobutylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene,
1-heptene, 1-octene, 1-nonene, 1-decene, and the like. In certain embodiments, the
α-olefins may be 1-Butene or 1-octene. Other suitable monomers include styrene, halo-or
alkyl-substituted styrenes, vinylbonzocyclobutane, 1,4-hexadiene, 1,7-octadiene, and
naphthenics (such as cyclopentene, cyclohexene, and cyclooctene, for example).
[0059] The multi-block interpolymers disclosed herein may be differentiated from conventional,
random copolymers, physical blends of polymers, and block copolymers prepared via
sequential monomer addition, fluxional catalysts, and anionic or cationic living polymerization
techniques. In particular, compared to a random copolymer of the same monomers and
monomer content at equivalent crystallinity or modulus, the interpolymers have better
(higher) heat resistance as measured by melting point, higher TMA penetration temperature,
higher high-temperature tensile strength, and/or higher high-temperature torsion storage
modulus as determined by dynamic mechanical analysis. Properties of infill may benefit
from the use of embodiments of the multi-block interpolymers, as compared to a random
copolymer containing the same monomers and monomer content, the multi-block interpolymers
have lower compression set, particularly at elevated temperatures, lower stress relaxation,
higher creep resistance, higher tear strength, higher blocking resistance, faster
setup due to higher crystallization (solidification) temperature, higher recovery
(particularly at elevated temperatures), better abrasion resistance, higher retractive
force, and better oil and filler acceptance.
[0060] Other olefin interpolymers include polymers comprising monovinylidene aromatic monomers
including styrene, o-methyl styrene, p-methyl styrene, t-butylstyrene, and the like.
In particular, interpolymers comprising ethylene and styrene may be used. In other
embodiments, copolymers comprising ethylene, styrene and a C
3-C
20 α-olefin, optionally comprising a C
4-C
20 diene, may be used.
[0061] Suitable non-conjugated diene monomers may include straight chain, branched chain
or cyclic hydrocarbon diene having from 6 to 15 carbon atoms. Examples of suitable
non-conjugated dienes include, but are not limited to, straight chain acyclic dienes,
such as 1,4-hexadiene, 1,6-octadiene, 1,7-octadiene, 1,9-decadiene, branched chain
acyclic dienes, such as 5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene; 3,7-dimethyl-1,7-octadiene
and mixed isomers of dihydromyricene and dihydroocinene, single ring alicyclic dienes,
such as 1,3-cyclopentadiene; 1,4-cyclohexadiene; 1,5-cyclooctadiene and 1,5-cyclododecadiene,
and multi-ring alicyclic fused and bridged ring dienes, such as tetrahydroindene,
methyl tetrahydroindene, dicyclopentadiene, bicyclo-(2,2,1)-hepta-2,5-diene; alkenyl,
alkylidene, cycloalkenyl and cycloalkylidene norbornenes, such as 5-methylene-2-norbornene
(MNB); 5-propenyl-2-norbornene, 5-isopropylidene-2-norbornene, 5-(4-cyclopentenyl)-2-norbornene,
5-cyclohexylidene-2-norbornene, 5-vinyl-2-norbornene, and norbornadiene. Of the dienes
typically used to prepare EPDMs, the particularly preferred dienes are 1,4-hexadiene
(HD), 5-ethylidene-2-norbornene (ENB), 5-vinylidene-2-norbomene (VNB), 5-methylene-2-norbornene
(MNB), and dicyclopentadiene (DCPD).
[0062] One class of desirable polymers that may be used in accordance with embodiments disclosed
herein includes elastomeric interpolymers of ethylene, a C
3-C
20 α-olefin, especially propylene, and optionally one or more diene monomers. Preferred
α-olefins for use in this embodiment are designated by the formula CH
2=CHR*, where R* is a linear or branched alkyl group of from 1 to 12 carbon atoms.
Examples of suitable α-olefins include, but are not limited to, propylene, isobutylene,
1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. A particularly preferred
α-olefin is propylene. The propylene-based polymers are generally referred to in the
art as EP or EPDM polymers. Suitable dienes for use in preparing such polymers, especially
multi-block EPDM type polymers include conjugated or non-conjugated, straight or branched
chain-, cyclic- or polycyclicdienes comprising from 4 to 20 carbons. Preferred dienes
include 1,4-pentadiene, 1,4-hexadiene, 5-ethylidene-2-norbornene, dicyclopentadiene,
cyclohexadiene, and 5-butylidene-2-norbornene. A particularly preferred diene is 5-ethylidene-2-norbornene.
[0063] In select embodiments, the thermoplastic resin is formed from ethylene-alpha olefin
copolymers or propylene-alpha olefin copolymers. In particular, in select embodiments,
the thermoplastic resin includes one or more non-polar polyolefins.
[0064] The olefin polymers, copolymers, interpolymers, and multi-block interpolymers may
be functionalized by incorporating at least one functional group in its polymer structure.
Exemplary functional groups may include, for example, ethylenically unsaturated mono-
and di-functional carboxylic acids, ethylenically unsaturated mono- and di-functional
carboxylic acid anhydrides, salts thereof and esters thereof. Such functional groups
may be grafted to an olefin polymer, or it may be copolymerized with ethylene and
an optional additional comonomer to form an interpolymer of ethylene, the functional
comonomer and optionally other comonomer(s). Means for grafting functional groups
onto polyethylene are described for example in
U.S. Patents Nos. 4,762,890,
4,927,888, and
4,950,541, the disclosures of which are incorporated herein by reference in their entirety.
One particularly useful functional group is maleic anhydride.
[0065] The amount of the functional group present in the functional polymer may vary. The
functional group may be present in an amount of at least about 0.25 weight percent
in some embodiments; at least about 5 weight percent in other embodiments; and at
least about 7 weight percent in yet other embodiments. The functional group may be
present in an amount less than about 40 weight percent in some embodiments; less than
about 30 weight percent in other embodiments; and less than about 25 weight percent
in yet other embodiments.
[0066] In certain embodiments, the thermoplastic resin may be an ethylene-octene copolymer
or interpolymer having a density between 0.857 and 0.911 g/cc and melt index (190°C
with 2.16 kg weight) from 0.1 to 100 g/10 min. In other embodiments, the ethylene-octene
copolymers may have a density between 0.857 and 0.902 g/cc and melt index (190°C with
2.16 kg weight) from 0.8 to 35 g/10 min.
[0067] In certain embodiments, the thermoplastic resin may be a propylene-ethylene copolymer
or interpolymer having an ethylene content between 5 and 20% by weight and a melt
flow rate (230°C with 2.16 kg weight) from 0.5 to 300 g/10 min. In other embodiments,
the propylene-ethylene copolymer or interpolymer may have an ethylene content between
5 and 12% by weight and a melt flow rate (230°C with 2,16 kg weight) from 1 to 100
g/10 min.
[0068] In certain other embodiments, the thermoplastic resin may be a low density polyethylene
having a density between 0.911 and 0.925 g/cc and melt index (190°C with 2.16 kg weight)
from 0.1 to 100 g/10 min.
[0069] In other embodiments, the thermoplastic resin may have a crystallinity of less than
50 percent. In preferred embodiments, the crystallinity of the base polymer may be
from 5 to 35 percent. In more preferred embodiments, the crystallinity may range from
7 to 20 percent.
[0070] In certain other embodiments, the thermoplastic resin is a semi-crystalline polymer
and may have a melting point of less than 110°C. In preferred embodiments, the melting
point may be from 25 to 100°C. In more preferred embodiments, the melting point may
be between 40 and 85°C.
[0071] In other embodiments, the thermoplastic resin is a glassy polymer and may have a
glass transition temperature of less than 110°C. In preferred embodiments, the glass
transition temperature may be from 20 to 100°C. In more preferred embodiments, the
glass transition temperature may be from 50 to 75°C.
[0072] In certain embodiments, the thermoplastic resin may have a weight average molecular
weight greater than 10,000 g/mole. In other embodiments, the weight average molecular
weight may be from 20,000 to 150,000 g/mole; in yet other embodiments, from 50,000
to 100,000 g/mole.
[0073] The one or more thermoplastic resins may be contained within the aqueous dispersion
in an amount from about 1% by weight to about 96% by weight. For instance, the thermoplastic
resin may be present in the aqueous dispersion in an amount from about 10% by weight
to about 60% by weight, and about 20% to about 50% by weight in another embodiment.
[0074] In a particular embodiment, the polyolefin resin may include copolymers and interpolymers
of ethylene and/or propylene and other monomers selected from C
4 to C
10 olefins, preferably alpha-olefins, more preferably from C
4 to C
8 alpha-olefins and most preferably selected from
n-butene,
n-hexene and n-octene. The ethylene or propylene content of the resin may range from
about 2 to 98 weight percent of the resin. In some embodiments, a primarily ethylene-based
polyolefin may be selected in which ethylene comprises from about 98 to 50 weight
percent of the polyolefin. In other embodiments, a primarily propylene-based or other
polyolefin may be selected in which propylene comprises from about 98 to 50 percent
of the polyolefin. Selected comonomer(s) may comprise the remainder of the polyolefin.
[0075] In one embodiment, the polyolefin resin may include an ethylene-based polyolefin
which has a melt index ("MI") determined according to ASTM D1238 (190°C with a 2.16
kg weight) from about 0.1 to 25g/10min; from 0.25 to 22 g/10 min in another embodiment;
and from about 0.5 to 18 g/10min in yet another embodiment. In another embodiment,
the polyolefin resin may include a propylene-based polyolefin which has a Melt Flow
Rate ("MFR") determined according to ASTM D1238 (230°C with 2.16 kg weight) of from
about 0.25 to 85 g/10min; from about 0.7 to 70 g/10min in another embodiment; from
about 1.4 to 60 in yet another embodiment; and from about 2 to 50 g/10min in yet another
embodiment.
[0076] In one embodiment, the polyolefin resin may comprise an ethylene-based polyolefin
having a density ranging from about 0.855 to 0.925 g/cc; from about 0.86 to 0.91 in
another embodiment; from about 0.875 to 0.905 in yet another embodiment; and from
about 0.86 to 0.90 in yet another embodiment.
[0077] One class of polyolefins particularly suited for use herein are copolymers of ethylene
and 1-octene or 1-butene, where ethylene comprises from about 50 to 90 percent by
weight of the copolymer in one embodiment, and from about 55 to 85 percent by weight
of the copolymer in another embodiment and 1-octene or 1-butene comprises from about
10 to 50 percent by weight of the copolymer in one embodiment and from about 15 to
45 percent by weight of the copolymer in another example, and where the ethylene copolymer
has a Melt Index ranging from about 0.25 to 30 g/10min in one embodiment, and 0.5
to 20 g/10min in another embodiment.
[0078] Another preferred class of polyolefins includes copolymers of 1-propene and ethylene,
1-octene, 1-hexene or 1-butene, where 1-propene comprises from about 65 to 95 percent
by weight of the copolymer in one embodiment in one embodiment, and from about 75
to 93 percent by weight of the copolymer in another embodiment and ethylene, 1-octene,
1-hexene or 1-butene comprise from about 5 to 35 percent by weight of the copolymer
in one embodiment, and from about 7 to 25 percent by weight of the copolymer in another
embodiment, and wherein the copolymer has a Melt Flow ranging from about 0.7 to 85
g/10min in one embodiment and from about 1.4 to 55 g/10min in another embodiment.
[0079] Ethylene-based polymers (including homopolymers, copolymer, interpolymers and block
interpolymers) useful in embodiments disclosed herein may have a melting temperature
(T
m) between 25°C and 130°C. In other embodiments, the ethylene-based polymers may have
a melting point of less than 125°C; less than 115°C in other embodiments; less than
105°C in other embodiments; less than 95°C in other embodiments; less than 85°C in
other embodiments; less than 75°C in other embodiments; less than 65°C in other embodiments;
and less than 60°C in yet other embodiments.
[0080] Ethylene-based polymers useful in embodiments disclosed herein may have a Vicat softening
point (ASTM D 1525) between 25°C and 130°C. In other embodiments, the ethylene-based
polymers may have a Vicat softening point of less than 125°C; less than 115°C in other
embodiments; less than 105°C in other embodiments; less than 95°C in other embodiments;
less than 85°C in other embodiments; less than 75°C in other embodiments; less than
65°C in other embodiments; and less than 60°C in yet other embodiments; less than
55°C in other embodiments; and less than 45°C in yet other embodiments.
[0081] Ethylene-based polymers useful in embodiments disclosed herein may have a heat deflection
temperature under load (DTUL) (ASTM D648, 0.45 MPa load) of at least 45°C. In other
embodiments, the ethylene-based polymers may have a DTUL between 45°C and 130°C. In
other embodiments, the ethylene-based polymers may have a DTUL between about 65°C
and about 120°C; and between about 75°C and about 110°C in other embodiments.
[0082] Propylene-based polymers (including homopolymers, copolymer, interpolymers and block
interpolymers) useful in embodiments disclosed herein may have a melting temperature
(T
m) between 25°C and 165°C. In other embodiments, the propylene-based polymers may have
a melting point of less than 135°C; less than 125°C in other embodiments; less than
115°C in other embodiments; less than 105°C in other embodiments; less than 95°C in
other embodiments; less than 90°C in other embodiments; less than 85°C in other embodiments;
less than 75°C in other embodiments; less than 65°C in other embodiments; and less
than 60°C in yet other embodiments.
[0083] Propylene-based polymers useful in embodiments disclosed herein may have a Vicat
softening point (ASTM D 1525) between 25°C and 160°C. In other embodiments, the propylene-based
polymers may have a Vicat softening point of less than 135°C; less than 125°C in other
embodiments; less than 115°C in other embodiments; less than 105°C in other embodiments;
less than 95°C in other embodiments; less than 90°C in other embodiments; less than
85°C in other embodiments; less than 75°C in other embodiments; less than 65°C in
other embodiments; less than 55°C in other embodiments; and less than 45°C in yet
other embodiments.
[0084] Propylene-based polymers useful in embodiments disclosed herein may have a heat deflection
temperature under load (DTUL) (ASTM D648, 0.45 MPa load) of at least 45°C. In other
embodiments, the propylene-based polymers may have a DTUL between 45°C and 130°C.
In other embodiments, the ethylene-based polymers may have a DTUL between about 65°C
and about 120°C; and between about 75°C and about 110°C in other embodiments.
[0085] Polymers suitable for blending with the above described polymers include thermoplastic
and non-thermoplastic polymers including natural and synthetic polymers. Exemplary
polymers for blending include ethylene-vinyl acetate (EVA), ethylene/ vinyl alcohol
copolymers, polystyrene, impact modified polystyrene, ABS, styrene/butadiene block
copolymers and hydrogenated derivatives thereof (SBS and SEBS), and thermoplastic
polyurethanes.
[0086] Suitable conventional block copolymers which may be blended with the polymers disclosed
herein may possess a Mooney viscosity (ML 1+4 @ 100°C.) in the range from 10 to 135
in some embodiments; from 25 to 100 in other embodiments; and from 30 to 80 in yet
other embodiments. Suitable polyolefins especially include linear or low density polyethylene,
polypropylene (including atactic, isotactic, syndiotactic and impact modified versions
thereof) and poly(4-methyl-1-pentene). Suitable styrenic polymers include polystyrene,
rubber modified polystyrene (HIPS), styrene/acrylonitrile copolymers (SAN), rubber
modified SAN (ABS or AES) and styrene maleic anhydride copolymers.
[0087] Dispersion Stabilizing Agent
[0088] Embodiments disclosed herein use a stabilizing agent to promote the formation of
a stable dispersion or emulsion. In select embodiments, the stabilizing agent may
be a surfactant, a polymer (different from the thermoplastic resin or base polymer
detailed above), or mixtures thereof In other embodiments, the resin is a self-stabilizer,
so that an additional exogenous stabilizing agent may not be necessary. For example,
a self-stabilizing system may include a partially hydrolyzed polyester, where by combining
polyester with an aqueous base, a polyester resin and surfactant-like stabilizer molecule
may be produced. In particular, the stabilizing agent may be used as a dispersant,
a surfactant for the frothing of a foam formed from the dispersion, or may serve both
purposes. In addition, one or more stabilizing agents may be used in combination.
[0089] In certain embodiments, the stabilizing agent may be a polar polymer, having a polar
group as either a comonomer or grafted monomer. In preferred embodiments, the stabilizing
agent may include one or more polar polyolefins, having a polar group as either a
comonomer or grafted monomer. Typical polymers include ethylene-acrylic acid (EAA)
and ethylene-methacrylic acid copolymers, such as those available under the trademarks
PRIMACOR™ (trademark of The Dow Chemical Company), NUCREL™ (trademark of E.I. DuPont
de Nemours), and ESCOR™ (trademark of ExxonMobil) and described in
U.S. Pat. Nos. 4,599,392,
4,988,781, and
5,938,437, each of which is incorporated herein by reference in its entirety. Other suitable
polymers include ethylene ethyl acrylate (EEA) copolymer, ethylene methyl methacrylate
(EMMA), and ethylene butyl acrylate (EBA). Other ethylene-carboxylic acid copolymer
may also be used. Those having ordinary skill in the art will recognize that a number
of other useful polymers may also be used.
[0090] If the polar group of the polymer is acidic or basic in nature, the stabilizing agent
polymer may be partially or fully neutralized with a neutralizing agent to form the
corresponding salt. In certain embodiments, neutralization of the stabilizing agent,
such as a long chain fatty acid or EAA, may be from 25 to 200% on a molar basis; from
50 to 110% on a molar basis in other embodiments. For example, for EAA, the neutralizing
agent is a base, such as ammonium hydroxide or potassium hydroxide, for example. Other
neutralizing agents can include lithium hydroxide or sodium hydroxide, for example.
Those having ordinary skill in the art will appreciate that the selection of an appropriate
neutralizing agent depends on the specific composition formulated, and that such a
choice is within the knowledge of those of ordinary skill in the art.
[0091] Where a polymeric stabilizing agent is used, the polymeric stabilizing agent may
have a molecular weight of between 5000 and 125000 in some embodiments. In other embodiments,
the polymeric stabilizing agent may have a molecular weight between about 5000 and
about 45000. In still other embodiments, the polymeric stabilizing agent may have
a molecular weight less than half that of the thermoplastic resin.
[0092] Other stabilizing agents that may be used include long chain fatty acids or fatty
acid salts having from 12 to 60 carbon atoms. In other embodiments, the long chain
fatty acid or fatty acid salt may have from 12 to 40 carbon atoms. The salts may be
alkali metal or ammonium salts of the fatty acid, prepared by neutralization of the
acid with the corresponding base, e.g., NaOH, KOH, NH
4OH, and amines, such as ethanol amine, triethanol amine, and the like. These salts
may be formed in situ in the dispersion step, as described more fully below. The appropriate
fatty acid stabilizing agent may be selected to serve as a dispersant for the extrusion
melt step in order to attain the desired average size of the particles, which in one
embodiment is between about 0.2 and 25 microns and between about 0.5 and 10 microns
in another embodiment. In another embodiment, the polyolefin particles may range in
size from 0.5 to 1.5 microns.
[0093] Additional stabilizing agents that may be useful include cationic surfactants, anionic
surfactants, or a non-ionic surfactants. Examples of anionic surfactants include sulfonates,
carboxylates, and phosphates. Examples of cationic surfactants include quaternary
amines. Examples of non-ionic surfactants include block copolymers containing ethylene
oxide and silicone surfactants. Surfactants useful as a stabilizing agent may be either
external surfactants or internal surfactants. External surfactants are surfactants
that do not become chemically reacted into the polymer during dispersion preparation.
Examples of external surfactants useful herein include salts of dodecyl benzene sulfonic
acid and lauryl sulfonic acid salt. Internal surfactants are surfactants that do become
chemically reacted into the polymer during dispersion preparation. An example of an
internal surfactant useful herein includes 2,2-dimethylol propionic acid and its salts.
[0094] In particular embodiments, the dispersing agent or stabilizing agent may be used
in an amount ranging from greater than zero to about 60% by weight based on the amount
of base polymer (or base polymer mixture) used. For example, long chain fatty acids
or salts thereof may be used from 0.5 to 10% by weight based on the amount of base
polymer. In other embodiments, ethylene-acrylic acid or ethylene-methacrylic acid
copolymers may be used in an amount from 0.5 to 60% by weight based on the amount
of the base polymer. In yet other embodiments, sulfonic acid salts may be used in
an amount from 0.5 to 10% by weight based on the amount of base polymer.
[0095] As discussed above, more than one stabilizing agent may be used, and combinations
may be used as a dispersant and as a surfactant, for example. One of ordinary skill
in the art will recognize that the stabilizing agent used to create a relatively stable
aqueous dispersion of polyolefin resin particles may vary depending on the nature
of the polyolefin particles employed. Additionally, the stabilizing agent used may
be the same or different than the frothing surfactant used in the preparation of a
froth from the dispersion.
[0096] Froth Stabilizing Surfactants
[0097] As discussed above, the coated or impregnated substrate may in some embodiments be
contacted with a froth or foam formed from dispersions disclosed herein. Embodiments
disclosed herein may use a froth stabilizing surfactant to promote the formation of
a stable dispersion and to aid in frothing. Creating and stabilizing the froth during
the frothing and drying steps may be accomplished by addition of a frothing surfactant
to the aqueous dispersion of the polyolefin resin when initially creating the froth.
In addition, these surfactants may also be used to improve aqueous wetting of dried
foams, if desired. Suitable frothing surfactants may be selected from cationic, nonionic
and anionic surfactants. In one embodiment, an anionic surfactant may be used.
[0098] In some embodiments, the frothing surfactant may be an alkylcellulose ethers, hydroxyalkyl
cellulose ethers, hydroxyalkyl alkylcellulose ethers, guar gum, xanthan gum, and polyoxyethylene
resins of at least 20,000 molecular weight, or combinations thereof Other suitable
frothing surfactants may be selected from cationic surfactants, anionic surfactants,
or a non-ionic surfactants. Examples of cationic surfactants include quaternary amines,
primary amine salts, diamine salts, and ethoxylated amines. Examples of non-ionic
surfactants include block copolymers containing ethylene oxide, silicone surfactants,
alkylphenol ethoxylates, and linear and secondary alcohol ethoxylates of alkyl group
containing more than 8 carbon atoms.
[0099] Examples of anionic surfactants include sulfonates, carboxylates, and phosphates.
In one embodiment, anionic surfactants useful in preparing the froth from the aqueous
dispersion may be selected from carboxylic acid salts and ester amides of carboxylic
fatty acids, preferably fatty acids comprising from 12-36 carbon atoms, e.g., stearic
or lauric acid, palmitic, myristic, oleic, linoleic, ricinoleic, erucic acid and the
like.
[0100] In some embodiments, the surfactant may include amphoteric surfactants such as aminopropionates,
amphoteric sulfonates, betaines, imidazoline based amphoterics, and sultaines, among
others. For example, the surfactant may be derived from an imidazoline and can either
be the acetate form (containing salt) or the propionate form (salt-free). Examples
of suitable amphoteric surfactants include surfactants such as lauramidopropyl betaine,
sodium laurimino dipropionate, cocoamidopropyl hydroxyl sultaine, alkylether hydroxypropyl
sultaine, sodium capryloampho hydroxypropyl sulfonate, disodium capryloampho dipropionate,
sodium cocoamphoacetate, disodium cocoamphodiacetate, sodium cocoamphopropionate,
disodium octyl iminodipropionate, sodium cocoampho hydroxypropyl sulfonate, disodium
lauryl iminodipropionate, sodium stearoampho acetate, and disodium tallow iminodipropionate,
among others. Other amphoteric surfactants known in the art may also be used.
[0101] Surfactants useful as a froth stabilizing agent may be either external surfactants
or internal surfactants. External surfactants are surfactants that do not become chemically
reacted into the polymer during dispersion preparation. Examples of external surfactants
useful herein include salts of dodecyl benzene sulfonic acid and lauryl sulfonic acid
salt. Internal surfactants are surfactants that do become chemically reacted into
the polymer during dispersion preparation. An example of an internal surfactant useful
herein includes 2,2-dimethylol propionic acid and its salts.
[0102] Surfactants useful for preparing a stable froth may also be referred to herein as
foam stabilizers. Those having ordinary skill in this field will recognize that a
number of foam stabilizers may be used. Foam stabilizers may include, for example,
sulfates, succinamates, and sulfosuccinamates.
[0104] Other conventional additives can be included with our dispersion to form a coating
composition. These include, but are not limited to, fillers, flame retardants (such
as calcium carbonate, aluminum trihydrate (ATH), and magnesium hydroxide), stabilizers,
pigments and dyes, mold release agents, and anti-stat agents. Other polymer or cellulosic
based fiber compositions may be used in combination with the glass fibers.
[0105] Additives may be combined with the dispersion, or with the thermoplastic resins,
stabilizing agents, or fillers used in the dispersion. For example, additives may
include a wetting agent, fire retardants, surfactants, anti-static agents, antifoam
agent, anti block, wax-based dispersion, pigments, a neutralizing agent, a thickener,
a compatibilizer, a brightener, a rheology modifier, a biocide, a fungicide, reinforcing
fibers, and other additives known to those skilled in the art. While optional for
purposes of the present invention, other components may be highly advantageous for
product stability during and after the manufacturing process.
[0106] Additives and adjuvants may be included in any formulation comprising the above described
polymers, copolymers, interpolymers, and multi-block interpolymers. Suitable additives
include fillers, such as organic or inorganic particles, including clays, talc, titanium
dioxide, zeolites, powdered metals, organic or inorganic fibers, including carbon
fibers, silicon nitride fibers, steel wire or mesh, and nylon or polyester cording,
nano-sized particles, clays, and so forth; tackifiers, oil extenders, including paraffinic
or napthelenic oils; and other natural and synthetic polymers, including other polymers
according to embodiments of the present disclosure. Thermoplastic compositions according
to other embodiments of the present disclosure may also contain organic or inorganic
fillers or other additives such as starch, talc, calcium carbonate, polymeric fibers
(including nylon, rayon, cotton, polyester, and polyaramide), metal fibers, flakes
or particles, expandable layered silicates, phosphates or carbonates, such as clays,
mica, silica, alumina, aluminosilicates or aluminophosphates, carbon whiskers, carbon
fibers, nanoparticles including nanotubes, wollastonite, graphite, zeolites, and ceramics,
such as silicon carbide, silicon nitride or titania. Silane-based or other coupling
agents may also be employed for better filler bonding.
[0107] The polymers and polymer blend compositions described above may contain processing
oils, plasticizers, and processing aids. Rubber processing oils having a certain ASTM
designation and paraffinic, napthenic or aromatic process oils are all suitable for
use. Generally from 0 to 150 parts, more preferably 0 to 100 parts, and most preferably
from 0 to 50 parts of processing oils, plasticizers, and/or processing aids per 100
parts of total polymer are employed. Higher amounts of oil may tend to improve the
processing of the resulting product at the expense of some physical properties. Additional
processing aids include conventional waxes, fatty acid salts, such as calcium stearate
or zinc stearate, (poly)alcohols including glycols, (poly)alcohol ethers, including
glycol ethers, (poly)esters, including (poly)glycol esters, and metal salt-, especially
Group 1 or 2 metal or zinc-, salt derivatives thereof.
[0108] For conventional TPO, TPV, and TPE applications, carbon black is one additive useful
for UV absorption and stabilizing properties. Representative examples of carbon blacks
include ASTM N110, N 121, N220, N231, N234, N242, N293, N299, S315, N326, N330, M332,
N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754,
N762, N765, N774, N787, N907, N908, N990 and N991
- These carbon blacks have iodine absorptions ranging from 9 to 145 g/kg and average
pore volumes ranging from 10 to 150 cm
3/100 g. Generally, smaller particle sized carbon blacks are employed, to the extent
cost considerations permit. For many such applications the present polymers and blends
thereof require little or no carbon black, thereby allowing considerable design freedom
to include alternative pigments or no pigments at all.
[0109] Compositions, including thermoplastic blends according to embodiments of the invention
may also contain anti-ozonants or anti-oxidants that are known to a rubber chemist
of ordinary skill. The anti-ozonants may be physical protectants such as waxy materials
that come to the surface and protect the part from oxygen or ozone or they may be
chemical protectors that react with oxygen or ozone. Suitable chemical protectors
include styrenated phenols, butylated octylated phenol, butylated di(dimethylbenzyl)
phenol, p-phenylenediamines, butylated reaction products of p-cresol and dicyclopentadiene
(DCPD), polyphenolic anitioxidants, hydroquinone derivatives, quinoline, diphenylene
antioxidants, thioester antioxidants, and blends thereof. Some representative trade
names of such products are WINGSTAY™ S antioxidant, POLYSTAY™ 100 antioxidant, POLYSTAY™
100 AZ antioxidant, POLYSTAY™ 200 antioxidant, WINGSTAY™ L antioxidant, WINGSTAY™
LHLS antioxidant, WINGSTAY™ K antioxidant, WINGSTAY™ 29 antioxidant, WINGSTAY™ SN-1
antioxidant, and IRGANOX™ antioxidants. In some applications, the anti-oxidants and
anti-ozonants used will preferably be non-staining and non-migratory.
[0110] For providing additional stability against UV radiation, hindered amine light stabilizers
(HALS) and UV absorbers may be also used. Suitable examples include TINUVIN™ 123,
TINUVIN™ 144, TINUVIN™ 622, TINUVIN™ 765, TINUVIN™ 770, and TINUVIN™ 780, available
from Ciba Specialty Chemicals, and CHEMISORB™ T944, available from Cytex Plastics,
Houston TX, USA. A Lewis acid may be additionally included with a HALS compound in
order to achieve superior surface quality, as disclosed in
U.S. Patent No. 6,051,681. Other embodiments may include a heat stabilizer, such as IRGANOX™ PS 802 FL, for
example.
[0111] For some compositions, additional mixing processes may be employed to pre-disperse
the heat stabilizers, anti-oxidants, anti-ozonants, carbon black, UV absorbers, and/or
light stabilizers to form a masterbatch, and subsequently to form polymer blends therefrom.
[0112] Suitable crosslinking agents (also referred to as curing or vulcanizing agents) for
use herein include sulfur based, peroxide based, or phenolic based compounds. Examples
of the foregoing materials are found in the art, including in
U.S. Patents No.: 3,758,643,
3,806,558,
5,051,478,
4,104,210,
4,130,535,
4,202,801,
4,271,049,
4,340,684,
4,250,273,
4,927,882,
4,311,628 and
5,248,729.
[0113] When sulfur based curing agents are employed, accelerators and cure activators may
be used as well. Accelerators are used to control the time and/or temperature required
for dynamic vulcanization and to improve the properties of the resulting cross-linked
article. In one embodiment, a single accelerator or primary accelerator is used. The
primary accelerator(s) may be used in total amounts ranging from about 0.5 to about
4, preferably about 0.8 to about 1.5 phr, based on total composition weight. In another
embodiment, combinations of a primary and a secondary accelerator might be used with
the secondary accelerator being used in smaller amounts, such as from about 0.05 to
about 3 phr, in order to activate and to improve the properties of the cured article.
Combinations of accelerators generally produce articles having properties that are
somewhat better than those produced by use of a single accelerator. In addition, delayed
action accelerators may be used which are not affected by normal processing temperatures
yet produce a satisfactory cure at ordinary vulcanization temperatures. Vulcanization
retarders might also be used. Suitable types of accelerators that may be used in the
present invention are amines, disulfides, guanidines, thioureas, thiazoles, thiurams,
sulfenamides, dithiocarbamates and xanthates. Preferably, the primary accelerator
is a sulfenamide. If a second accelerator is used, the secondary accelerator is preferably
a guanidine, dithiocarbamate or thiuram compound. Certain processing aids and cure
activators such as stearic acid and ZnO may also be used. When peroxide based curing
agents are used, co-activators or coagents may be used in combination therewith. Suitable
coagents include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate
(TMPTMA), triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), among others. Use
of peroxide crosslinkers and optional coagents used for partial or complete dynamic
vulcanization are known in the art and disclosed for example in the publication, "
Peroxide Vulcanization of Elastomer", Vol. 74, No 3, July-August 2001.
[0114] When the polymer composition is at least partially crosslinked, the degree of crosslinking
may be measured by dissolving the composition in a solvent for specified duration,
and calculating the percent gel or unextractable component. The percent gel normally
increases with increasing crosslinking levels. For cured articles according to
embodiments of the invention, the percent gel content is desirably in the range from
5 to 100 percent.
[0115] In some embodiments, additives may also include perfumes, algae inhibitors, anti-microbiological
and anti-fungus agents, flame retardants and halogen-free flame retardants, as well
as slip and anti-block additives. Other embodiments may include PDMS to decrease the
abrasion resistance of the polymer. Adhesion of the polymer to the sand may also be
improved through the use of adhesion promoters or functionalization or coupling of
the< polymer with organosilane, polychloroprene (neoprene), or other grafting agents.
[0116] Dispersion Formulations
[0117] Dispersion formulations in accordance with embodiments disclosed herein may include
a liquid medium, such as water, a thermoplastic resin, a dispersion stabilizing agent,
and optionally a filler. With respect to the thermoplastic resin and the dispersion
stabilizing agent, in some embodiments, the thermoplastic resin may comprise between
about 30% to 99% (by weight) of the total amount of thermoplastic resin and dispersion
stabilizing agent in the composition. In other embodiments, the thermoplastic resin
may comprise between about 50% and about 80% (by weight) of the total amount of thermoplastic
resin and dispersion stabilizing agent in the composition. In yet other embodiments,
the thermoplastic resins may comprise about 70% (by weight) of the total amount of
thermoplastic resin and dispersion stabilizing agent in the composition.
[0118] In one embodiment, the aqueous dispersion disclosed herein may include polyolefin
resin particles ranging in size from about 0.2 to 10 microns; from about 0.5 to 5
microns in another embodiment; and from about 1 to 2 microns. Thus, in comparison
to the glass-based fibers or glass-containing substrate coated or impregnated with
the dispersion, the polyolefin resin particles are generally at least an order of
magnitude smaller.
[0119] The thermoplastic resin and the dispersion stabilizing agent are preferably dispersed
in a liquid medium, which in some embodiments is water. In some embodiments, sufficient
base is added to neutralize the resultant dispersion to achieve a pH range of about
6 to about 14. In particular embodiments, sufficient base is added to maintain a pH
between about 9 to about 12. Water content of the dispersion may be controlled so
that the combined content of the thermoplastic resin and the dispersion stabilizing
agent (solids content) is between about 1% to about 74% (by volume). In another embodiment,
the solids content ranges between about 25% to about 74% (by volume). In yet another
embodiment, the solid content ranges between about 30% to about 50% (without filler,
by weight). In yet another embodiment, the solids content ranges is between about
40% to about 55% (without filler, by weight).
[0120] In various embodiments, a dispersion may be formed from a non-functionalized or non-polar
thermoplastic resin and a functionalized or polar dispersion stabilizing agent. In
some embodiments, the thermoplastic resin and the dispersion stabilizing agent may
form two distinct phases within the dispersion. In other embodiments, the thermoplastic
resin and the dispersion stabilizing agent may form two distinct phases when applied
to a substrate. The two distinct phases may be present prior to, during, or subsequent
to removal of water from the dispersion coated substrate.
[0121] Dispersions formed in accordance with embodiments disclosed herein may be characterized
in having an average particle size of between about 0.3 to about 3.0 microns. In other
embodiments, dispersions may have an average particle size of from about 0.8 to about
1.2 microns. "Average particle size" as used herein means the volume-mean particle
size. In order to measure the particle size, laser-diffraction techniques may be employed
for example. A particle size in this description refers to the diameter of the polymer
in the dispersion. For polymer particles that are not spherical, the diameter of the
particle is the average of the long and short axes of the particle. Particle sizes
can be measured on a Beckman-Coulter LS230 laser-diffraction particle size analyzer
or other suitable device.
[0122] In preferred formulations, therefore, dispersions in accordance with the present
disclosure may include a thermoplastic resin, which may include at least one non-polar
polyolefin described above, a dispersion stabilizing agent, which may include at least
one polar polyolefin, and optionally a filler. With respect to the thermoplastic resin
and the dispersion stabilizing agent, in preferred embodiments, the at least one non-polar
polyolefin may comprise between about 30% to 99% (by weight) of the total amount of
base polymer and dispersion stabilizing agent in the composition. More preferably,
the at least one non-polar polyolefin comprises between about 50% and about 80%. Still
more preferably, the one or more non-polar polyolefins comprise about 70%.
[0123] With respect to the filler, typically, an amount greater than about 0 to about 1000
parts per hundred of the combined amount of thermoplastic resin and dispersion stabilizing
agent is used. In selected embodiments, between about 50 to 250 parts per hundred
are used; between about 10 to 500 parts per hundred in other embodiments; between
about 20 to 400 parts per hundred in other embodiments; and between about 0 to about
200 parts per hundred in yet other embodiments.
[0124] In certain embodiments, a structure or textile, such as a glass-based fiber or a
glass-containing substrate, coated or impregnated with a compound may have a combined
amount of the at least one thermoplastic resin and the dispersion stabilizing agent
in the range of about 0.1 to about 150 parts per hundred parts by weight of the structure
or textile. In other embodiments, a structure or textile impregnated with a compound
may have a combined amount of the at least one polymer and the dispersion stabilizing
agent in the range of about 0.5 to about 10 parts per hundred parts by weight of the
structure or textile; and from about 1.0 to about 8.0 parts in other embodiments.
[0125] Dispersion formulations disclosed herein may include surfactants, frothing agents,
dispersants, thickeners, fire retardants, pigments, antistatic agents, reinforcing
fibers, antioxidants, a neutralizing agent, a rheology modifier, preservatives, biocides,
acid scavengers, a wetting agent, and the like. While optional for purposes of the
present invention, other components may be highly advantageous for product stability
during and after the manufacturing process.
[0126] In addition, embodiments of the dispersions optionally include a filler wetting agent.
A filler wetting agent generally may help make the filler and the polyolefin dispersion
more compatible. Useful wetting agents include phosphate salts, such as sodium hexametaphosphate.
A filler wetting agent can be included in a composition of the present invention at
a concentration of at least about 0.5 part per 100 parts of filler, by weight.
[0127] Furthermore, embodiments of the dispersion may optionally include a thickener. Thickeners
may be useful to increase the viscosity of low viscosity dispersions. Thickeners suitable
for use may be any known in the art such as for instance poly-acrylate type or associate
non-ionic thickeners such as modified cellulose ethers. For example, suitable thickeners
include ALCOGUM™ VEP-II (trade name of Alco Chemical Corporation), RHEOVIS™ and VISCALEX™
(trade names of Ciba Ceigy), UCAR
® Thickener 146, or ETHOCELL™ or METHOCELL™ (trade names of the Dow Chemical Company)
and PARAGUM™ 241 (trade name of Para-Chem Southern, Inc.), or BERMACOL™ (trademark
of Akzo Nobel) or AQUALON™ (trademark of Hercules) or ACUSOL
® (trademark of Rohm and Haas). Thickeners may be used in any amount necessary to prepare
a dispersion of desired viscosity.
[0128] The ultimate viscosity of the dispersion is, therefore, controllable. Addition of
the thickener to the dispersion including the amount of filler may be performed with
conventional means to result in viscosities as needed. Viscosities of thus dispersions
may reach +3000 cP (Brookfield spindle 4 with 20 rpm) with moderate thickener dosing
(up to 4 % preferably, below 3% based on 100phr of polymer dispersion). The starting
polymer dispersion as described may have an initial viscosity prior to formulation
with fillers and additives between 20 and 1000 cP (Brookfield viscosity measured at
room temperature with spindle RV3 at 50 rpm). Still more preferably, the starting
viscosity of the dispersion maybe between about 100 to about 600 cP.
[0129] Also, embodiments of the present disclosure may be characterized by their stability
when a filler is added to the thermoplastic resin / dispersion stabilizing agent mixture.
In this context, stability refers to the stability of viscosity of the resultant aqueous
polyolefin dispersion. In order to test the stability, the viscosity is measured over
a period of time. Preferably, viscosity measured at 20°C should remain +/- 10% of
the original viscosity over a period of 24 hours, when stored at ambient temperature.
[0130] In a specific embodiment, a thermoplastic resin and a dispersion stabilizing agent
are melt-kneaded in an extruder along with water and a neutralizing agent, such as
ammonia, potassium hydroxide, or a combination of the two to form a dispersion. Those
having ordinary skill in the art will recognize that a number of other neutralizing
agents may be used. In some embodiments, a filler may be added during or after blending
the thermoplastic resin and dispersion stabilizing agent.
[0131] Any melt-kneading means known in the art may be used. In some embodiments, a kneader,
a BANBURY
® mixer, single-screw extruder, or a multi-screw extruder is used. A process for producing
the dispersions in accordance with the present invention is not particularly limited.
One preferred process, for example, is a process comprising melt-kneading the above-mentioned
components according to
U.S. Patent No. 5,756,659 and
U.S. Patent No. 6,455,636.
[0132] Figure 1 schematically illustrates an extrusion apparatus that may be used in embodiments
of the invention. An extruder 20, in certain embodiments a twin screw extruder, is
coupled to a back pressure regulator, melt pump, or gear pump 30. Embodiments also
provide a base reservoir 40 and an initial water reservoir 50, each of which includes
a pump (not shown). Desired amounts of base and initial water are provided from the
base reservoir 40 and the initial water reservoir 50, respectively. Any suitable pump
may be used, but in some embodiments a pump that provides a flow of about 150 cc/min
at a pressure of 240 bar is used to provide the base and the initial water to the
extruder 20. In other embodiments, a liquid injection pump provides a flow of 300
cc/min at 200 bar or 600 cc/min at 133 bar. In some embodiments, the base and initial
water are preheated in a preheater.
[0133] Resin in the form of pellets, powder or flakes is fed from the feeder 80 to an inlet
90 of the extruder 20 where the resin is melted or compounded. In some embodiments,
the dispersion stabilizing agent is added to the thermoplastic resin through and along
with the resin, and in other embodiments, the dispersion stabilizing agent is provided
separately to the twin screw extruder 20. The resin melt is then delivered from the
mix and convey zone to an emulsification zone of the extruder where the initial amount
of water and base from the reservoirs 40 and 50 is added through inlet 55. In some
embodiments, dispersion stabilizing agent may be added additionally or exclusively
to the water stream. In some embodiments, the emulsified mixture is further diluted
with additional water inlet 95 from reservoir 60 in a dilution and cooling zone of
the extruder 20. Typically, the dispersion is diluted to at least 30 weight percent
water in the cooling zone. In addition, the diluted mixture may be diluted any number
of times until the desired dilution level is achieved. In some embodiments, water
is not added into the twin screw extruder 20 but rather to a stream containing the
resin melt after the melt has exited from the extruder. In this manner, steam pressure
build-up in the extruder 20 is eliminated.
[0134] Advantageously, by using an extruder in certain embodiments, the thermoplastic resin
and the dispersion stabilizing agent may be blended in a single process to form a
dispersion. Also, advantageously, by using one or more of the dispersion stabilizing
agents listed above, the dispersion may be stable with respect to the filler and other
additives.
[0135] Coating and Impregnation
[0136] Polyolefin dispersions formed in accordance with embodiments disclosed herein provide
the ability to coat, partially coat, apply the dispersion to, or impregnate the dispersion
into glass-based fibers and glass-containing substrates, films, sheets, fabrics, or
other glass-based articles. Polyolefin dispersions formed in accordance with embodiments
disclosed herein may also provide for imparting a modified property to a substrate.
For example, a dispersion-coated substrate may achieve good adhesive properties while
maintaining a flexible laminate.
[0137] The dispersion may be applied to various fibers including glass, polymeric, and cellulosics,
and articles such as mats, nonwovens, wovens, and fabrics made from such fibers. Glass-fiber
articles include, but are not limited to woven rovings, wet chopped strands, unidirectional
and multi-directional fabrics (biaxial, triaxial, quadraxial), paper dry chop, molding
mats, insulation, double bias fabrics, continuous strand mats, chopped strand mats,
veils, and chopped strands. The glass type used may be any of the standard silicon-based
glasses known in the art, such as E-glass, a low alkali glass.
[0138] In some embodiments, a polyolefin dispersion or dispersion compound (a dispersion
containing a filler) may be applied to a fibrous structure using any application method
known to those skilled in the art. In other embodiments, a fibrous structure may be
impregnated with a dispersion or a dispersion compound. In certain embodiments, fibrous
structures may include textiles, geotextiles, and natural fibers. In certain embodiments,
the fibrous structure may include cotton, wool, synthetic wool, cellulosics including
rayon, synthetic fibers of polyamide, polyacrylonitrile, polyvinyl chloride, polyvinylidene
chloride, polypropylenes, polyesters, or combinations thereof. In other embodiments,
the fibrous structure may be flax, hemp, cellulose, pulp, wood, or combinations thereof.
In other embodiments, the fibrous structures described above may be glass-reinforced.
In yet other embodiments, the fibrous structure may be a glass-based fiber or a glass-containing
substrate or textile.
[0139] For example, in the method as practiced in Figure 2, a continuous fiber strand, or
roving,
1 is fed from a supply reel
2 through a bath
4 containing an aqueous melt-kneaded thermoplastic dispersion
5 forming a coated strand. The coated strand is air dried or optionally passed through
a heat source such as an oven
6 in which the water of the dispersion is driven off, i.e., the strand is dried, and/or
the thermoplastic resin is fused. The coated strand after solidification of the thermoplastic
resin may optionally pass near one or more heaters
7 where the strand is further dried and/or the temperature of the strand is raised,
when required to an appropriate temperature wherein it will be ready for pelletizing
in unit
9 to form pellets of the long fiber-reinforced thermoplastic concentrate of the present
disclosure. The strand may be drawn through the apparatus by the pelletizing unit
9 or optionally, a draw-off device
8. Optionally, the coated strand may be passed through a shaping device
13 at any point between the bath
4 and the pelletizing unit
9.
[0140] Alternatively, in the method as practiced in Figure
3, a continuous fiber strand, or roving,
1 is fed from a supply reel
2 through a bath
4 containing an aqueous melt-kneaded thermoplastic dispersion
5. The coated strand is next passed through a pelletizer
9, or other chopping device, comminuting the coated strand into pre-dried pellets
11 which fall onto a conveyer belt
12 which allows for the pre-dried pellets to air dry or optionally passes the pre-dried
pellets
11 through a heat source such as an oven
6 in which the water of the dispersion may ben off, i.e., the pre-dried pellets
11 are dried, and/or the thermoplastic resin is fused providing pellets
10 of the long fiber-reinforced thermoplastic concentrates of the invention. If necessary,
the dried pellets may be scraped from the conveyer belt by a scraper
14. The strand may be drawn through the apparatus by the pelletizing unit
9 or optionally, a draw-off device
8.
[0141] Optionally, the coated strand may be passed through a shaping device
13 at any point between the bath 4 and the pelletizing unit
9. Any method to transport the predried pellets
11 to the oven
6 is acceptable, for example, conveyer belts or pneumatic transportation systems.
[0142] In some embodiments, at least a portion of the water in the dispersion applied may
be removed from the dispersion coated article. In other embodiments, at least 50 percent
of the water in the dispersion applied may be removed.
[0143] As a process for producing the dispersion-coated or impregnated structures disclosed
herein, a process other than the ones described hereinabove may be employed. For example,
the fiber bundle may be cut into a prescribed length to obtain chopped strands, then
a thermoplastic resin dispersion may be coated on the chopped strands by a method
such as spraying, followed by heating to obtain dried and/or fused pellets.
[0144] Where it is preferred to coat, apply, or impregnate the structure with a froth or
a foam prepared from a froth, a gas may be used as a frothing agent. Examples of suitable
frothing agents include: gases and/or mixtures of gases such as, air, carbon dioxide,
nitrogen, argon, helium, and the like. Particularly preferable is the use of air as
a frothing agent. Frothing agents are typically introduced by mechanical introduction
of a gas into a liquid to form a froth. This technique is known as mechanical frothing.
In preparing a frothed polyolefin backing, it is preferred to mix all components and
then blend the air or gas into the mixture, using equipment such as an OAKES, MONDO,
or FIRESTONE frother.
[0145] Application / Impregnation Control
[0146] The amount or degree to which a fibrous structure is impregnated or coated with the
dispersion may be controlled. For example, impregnation may be controlled by pressing
the fabric between calenders, removing excess material. Impregnation may additionally
be controlled, for example, by adjusting one or more of the viscosity of the compound,
the concentration of the combined polymer and stabilizer in the aqueous dispersion,
the speed of the substrate (fiber or textile) through the dispersion, the degree to
which the excess dispersion is wiped off by a suitable mechanism such as passing the
strand through a shaping device (
e.g., a restricting orifice), the concentration of the filler in the compound, or the
polarity of the aqueous dispersion.
[0147] In certain embodiments, the coated or impregnated substrate, such as glass-based
fibers or glass-containing substrates, may have a combined amount of the at least
one thermoplastic resin and the dispersion stabilizing agent in the range of about
0.1 to about 10 parts per hundred by weight of the coated or impregnated substrate;
0.5 to 8 parts per hundred in other embodiments; and 1 to 6 parts per hundred in yet
other embodiments. In other embodiments, the coated or impregnated substrate may contain
at least 92 weight percent glass based on a total weight of the substrate, the thermoplastic
resin, and the dispersion stabilizing agent; at least 94 weight percent glass in other
embodiments; at least 96 weight percent glass in other embodiments; and at least 98
weight percent glass in yet other embodiments. To maintain the desired degree of coating
or impregnation, for example, in certain embodiments, the thermoplastic resin may
be controlled in the range from about 35 to about 55 percent by weight of the aqueous
dispersion. In other embodiments, the thermoplastic resin may be controlled in the
range from about 40 to about 50 percent by volume of the aqueous dispersion. In other
embodiments, the viscosity of the dispersion may be controlled in the range from about
20 to about 3000 cP.
[0148] One skilled in the art will appreciate that a desirable degree or amount of impregnation
may range from a partial saturation of the fibrous structure to a complete saturation
of the fibrous structure. The desired degree of impregnation may depend upon variables
including the nature of the material being impregnated and the nature of impregnate,
for example. One skilled in the art will also appreciate that the intended end properties
of the impregnated structure will influence the selection of the specific ingredients
(substrates and dispersions, for example) and processing parameters.
[0149] The dispersion may be applied to the substrate, in some embodiments resulting in
a coating thickness of between 0.1 microns and 10 microns. In other embodiments, the
coating thickness may be at least 1 micron, at least 2 microns, or at least 5 microns.
[0150] The dispersion may be applied to the substrate, in some embodiments, resulting in
a coating weight of between 1 gram per square meter of substrate surface area and
100 grams per square meter of substrate surface area.
[0151] Coating or impregnating a substrate with the dispersions described above may modify
a property of the substrate. For example, a coating may provide adhesive properties
to the substrate for binding with a second substrate. In some embodiments, the coated
substrate may have an adhesive force of at least 0.7 lb/in when bound to a second
substrate. In other embodiments, the coated substrate may have an adhesive force between
0.7 1b/in and 1.1 1b/in when bound to a second substrate. In other embodiments, the
adhesive force of a coated substrate may be at least 10% greater than a binding force
of an uncoated substrate. The adhesive force, as used herein, is the force required
to separate the coated substrate from the second substrate.
[0152] Another example of modified properties a coating may promote or improve is compatibility
of the glass-based fibers or glass-containing substrates with other materials, such
as polypropylenes, nylons, and other fibers commonly used in textile applications.
[0153] As another example of modified properties, a coating or impregnation may improve
the tensile strength of the glass-based fibers or glass-containing substrate. In some
embodiments, the coated or impregnated substrate may have a tensile strength at least
10% greater than an uncoated or unimpregnated substrate.
[0154] In other embodiments, a coating or impregnation may serve to protect the substrate
from deleterious impacts or chemical attack. In yet other embodiments, the glass-based
or glass-containing articles may be formable, such that their shape may be modified
subsequent to the coating or impregnation with the dispersions described above. In
some embodiments, the articles may be formable using temperature and/or pressure.
In certain embodiments, the thermoforming temperature of the article may be within
50°C of the melting temperature of the thermoplastic resin.
[0155] Glass-based fibers, either coated alone or as part of a glass-containing article,
may have a diameter between 5 and 35 microns in some embodiments. In other embodiments,
the glass-based fibers may have a diameter between 10 and 30 microns.
[0156] Coated or impregnated glass-containing articles disclosed herein, including mats,
nonwovens, wovens, and fabrics may have a basis weight in the range from 25 to 1,000
g/m
2 in some embodiments. In other embodiments, the glass-containing articles may have
a basis weight between 30 and 950 g/m
2. In other embodiments, the articles may have a melting point of less than 110°C.
[0157] Coated or impregnated glass-containing articles disclosed herein may be formed using
the coating/binder in the dry state (coating directly onto the article/fiber) and
the wet state (chopped fibers are slurried with water and the binder and later dried
to form an article). The coating/binder may be applied between 0.05 and 20 percent
by weight in some embodiments. In other embodiments, the coating/binder may be applied
between 0.25 and 15 percent by weight; and between 0.45 and 10 percent by weight in
yet other embodiments.
[0158] In other embodiments, a substrate may be coated with at least one layer of the above
described dispersion. In other embodiments, the above described dispersion may be
used to adhere a glass-containing article or glass-based fiber to a second substrate,
such as a fabric.
[0159] In still other embodiments, a laminate may be formed where at least one layer of
the above described dispersion is disposed on at least one substrate. The at least
one substrate may be a glass-containing article, a glass-based fiber, a froth, a foam,
a thermoplastic sheet or film, a woven or non-woven fabric, fiberglass, or a melt
spunbonded or melt blown material.
[0160] In some embodiments, a laminate may be formed where at least one layer of the above
described dispersion is adhered to at least one substrate. In other embodiments, the
dispersions disclosed herein may be disposed between two substrate layers, which may
be the same or different substrates. In some embodiments, a coated article may be
immersed in or coated with a polymer.
[0161] In still other embodiments, a glass-containing article or a glass-based fiber may
be coated with two or more layers of the above described dispersions. In various embodiments,
the layers may be formed from the same or different dispersion, and may be of the
same or different coating thicknesses or coating weights.
[0164] A continuous glass roving strand (VETROTEX™ RO99 719 available from Saint-Gobain)
is unwound from the outside of a standard bobbin. The roving is pulled through an
aqueous melt kneaded thermoplastic dispersion as set forth in Figure 2 by a BRABENDERⓇ
film pull roll unit at a rate of 8 feet per minute (ft/min.). The aqueous dispersion
comprises 80 percent by weight deionized water and 20 percent by weight solids. The
solids comprise 2.35 weight percent long chain carboxylic acid surfactant and 17.65
weight percent of a propylene-rich propylene and ethylene copolymer (9 percent ethylene)
having a density of 0.876 grams per cubic centimeter (g/cc) and a melt flow rate (MFR)
(under conditions of 230°C and an applied load of 2.16 kilograms) of 25 grams per
10 minutes (g/10 min.). The average particle size of the dispersion is about 0.61
microns with a polydispersity of 1.31. The pH value of the melt-kneaded aqueous dispersion
is 11.6. The glass roving is pulled through the bath for a distance of about 75 mm.
After immersing into and exiting the bath, excess liquid is removed from the coated
strand by contact with a fluoropolymer wiper. The wet strand is pulled into a forced
air oven maintained at a temperature of 180°C. Inside the oven, the strand is passed
over a series of pulleys and guides to provide a sufficient path length for a one
minute residence time in the oven. In the oven, the water is driven off and the propylene
polymer softened and fused. The dry coated strand emerges from the oven tacky due
to the soften polymer coating on the glass fibers. The coated strand quickly cools
in the air to a stiff, flat bundle of coated glass fibers. The flat, coated bundle
of glass fibers is cut into 12 mm long glass fiber (LGF) concentrate pellets using
a air-powered fiberglass chopper gun. The BRABENDERⓇ puller is located after the oven
and before the chopper gun. The glass content of this sample is determined by ashing
the pellets at 550°C for two hours in a muffle furnace. The glass level is determined
as the residual weight after removal of the organic coating and is 90.8 percent.
[0165] The LGF concentrate pellets (33 parts) are dry blended with 7.5 parts polypropylene
homopolymer pellets (available from The Dow Chemical Company as 5E16S Polypropylene
Resin, 35 MFR - "5E16S"), 7.5 parts polypropylene homopolymer pellets (available from
The Dow Chemical Company as DX5E30S Polypropylene Resin, 75 MFR - "DX5E30S"), 2 parts
maleic anhydride grafted polypropylene pellets (available from Crompton as POLYBOND™
3200), and 50 parts polypropylene and ethylene copolymer pellets (available from The
Dow Chemical Company as 7C54H PolyPropylene Resin, 12 MFR - "7C54H") and shaken in
a plastic bag. This mixed pellet blend is placed in the feed hopper of a Toyo PLASTAR™
SI-90 plastic injection molding machine equipped with a mold containing twin drops
for a standard ASTM tensile-bar and a two inch diameter optical disk. Parts are molded
from this compound using a temperature profile of 395°F (202°C) closest to the hopper
to 385°F (196°C) by the nozzle. The mold temperature is 100°F, the hold time is 15
seconds, and the back pressure used is 250 pounds per square inch (psi). The parts
produced are off-white in color and homogeneous in appearance, with a smooth surface
and no visible accumulations of glass fiber.
[0167] Example 2 is run the same as Example 1 with the exception that the strand after exiting
the oven is passed though a rounding die and cools in the air to a stiff, round strand.
A Killion tube puller is utilized rather than the BRABENDER® film pull roll unit and
the Killion tube puller is located after the rounding die and before the cutter. The
glass level is determined to be 90.7 percent based on the weight of the long glass
thermoplastic concentrate.
[0169] Example 3 is run the same as Example 2 with the exception that the amounts of polypropylene
homopolymer pellets (5E16S), polypropylene homopolymer pellets (DX5E30S), and polypropylene
and ethylene copolymer pellets (7C54H) are 9, 9, and 47 weight percent, respectively.
The glass level in the concentrate is determined to be 90.7 percent based on the weight
of the long glass thermoplastic concentrate.
[0171] Example 4 is run the same as Example 2 with the exception that two glass roving strands
are coated. The glass level is determined to be 90.7 percent based on the weight of
the long glass thermoplastic concentrate.
[0172] The compositions of the LGF concentrates of Examples 1 to 4 are listed in Table 1.
The properties of molded test specimens comprising said LGF concentrates are tested
according to the following test methods and the properties are reported in Table 1.
Izod impact resistance as measured by the "notched" and "unnotched" Izod test is determined
according to ASTM D 256-90-B at 23°C. Notched specimens are notched with a TMI 22-05
notcher to give a 0.254 mm radius notch. A 0.91 kilogram pendulum is used. The values
are reported in foot pounds per inch (ft-lb/in).
[0173] "Dart" instrumented impact resistance is measured according to ASTM D 3763 on a MTS
810 instrumented impact tester at 15 miles per hour (MPH) impact. Test results are
determined at 23°C. Test results are reported in inch-pounds (in-lb).
[0174] Flexural modulus ("Fm") and flexural strength ("Fs") are measured according to ASTM
D 790. Test results are reported in pounds per square inch (psi).
[0175] Tensile elongation ("Te"), tensile modulus ("Tmod") and tensile strength ("Ts") are
measured according to ASTM D 638. Te results are reported in percent (%) and Tm and
Ts results are reported in psi.
[0176] Deflection temperature under load ("DTUL") is measured according to ASTM D 648 on
unannealed samples at 264 psi (1.8 mega Pascal (MPa)). Results are reported in degrees
Fahrenheit (°F).
[0177] "Ash" is measured according to ASTM D 5650 and is reported in %.
Table 1.
Example |
1 |
2 |
3 |
4 |
|
|
|
|
|
COMPONENT |
|
|
|
|
7C54H |
50 |
50 |
47 |
50 |
5E16S |
7.5 |
7.5 |
9 |
7.5 |
DX5E30S |
7.5 |
7.5 |
9 |
7.5 |
LGF-Single strand-flat . |
33 |
-- |
-- |
-- |
LGF-Single strand-round |
-- |
33 |
33 |
-- |
LGF-double strand-round |
-- |
-- |
-- |
33 |
POLYBOND™ 3200 |
2 |
2 |
2 |
2 |
|
|
|
|
|
PROPERTY |
|
|
|
|
Fm, 105 psi |
n/a* |
7.64 |
7.68 |
7.87 |
Fs, psi |
n/a |
18,500 |
18,700 |
18,700 |
Te, % |
n/a |
3 |
3 |
3 |
Tmod, 105 psi |
n/a |
7.88 |
8.05 |
6.92 |
Ts, psi |
n/a |
11,200 |
11,700 |
10,800 |
Notched Izod, ft-lb/in |
3.2 |
4.7 |
4.7 |
5.0 |
Unnotched Izod, ft-lb/in |
n/a |
14.9 |
15.9 |
16.1 |
|
|
|
|
|
DART |
|
|
|
|
Peak Energy, in-lb |
51 |
59 |
62 |
79 |
Total Energy, in-lb |
n/a |
301 |
301 |
303 |
DTUL, °F |
n/a |
301 |
301 |
303 |
[0179] A continuous glass roving strand (VETROTEX™ RO99 719 available from Saint-Gobain)
is unwound from the outside of a standard bobbin. The roving is pulled through an
aqueous melt kneaded thermoplastic dispersion as set forth in Figure 2 by a BRABENDER®
film pull roll unit at a rate of 8 feet per minute (ft/min). The aqueous dispersion
comprises 80 percent by weight deionized water and 20 percent by weight solids. The
solids comprise 2.35 weight percent long chain carboxylic acid surfactant and 17.65
weight percent of a propylene-rich propylene and ethylene copolymer (9 percent ethylene)
having a density of 0.876 grams per cubic centimeter (g/cc) and a melt flow rate (MFR)
(under conditions of 230°C and an applied load of 2.16 kilograms) of 25 grams per
10 minutes (g/10 min.). The average particle size of the dispersion is about 0.61
microns with a polydispersity of 1.31. The pH value of the melt-kneaded aqueous dispersion
is 11.6. The glass roving is pulled through the bath for a distance of about 75 mm.
After immersing into and exiting the bath, excess liquid is removed from the coated
strand by contact with a fluoropolymer wiper. The wet strand is pulled into a forced
air oven maintained at a temperature of 180°C. Inside the oven, the strand is passed
over a series of pulleys and guides to provide a sufficient path length for a one
minute residence time in the oven. In the oven, the water is driven off and the propylene
polymer softened and fused. The dry coated strand emerges from the oven tacky due
to the soften polymer coating on the glass fibers. The coated strand quickly cools
in the air to a stiff, flat bundle of coated glass fibers. The flat, coated bundle
of glass fibers is cut into 12 mm long glass fiber (LGF) concentrate pellets using
a air-powered fiberglass chopper gun. The BRABENDER® puller is located after the oven
and before the chopper gun. The glass content of this sample is determined by ashing
the pellets at 550°C for two hours in a muffle furnace. The glass level is determined
as the residual weight after removal of the organic coating and is 92.3 percent.
[0180] The LGF concentrate pellets (33 parts) are dry blended with 7.5 parts polypropylene
homopolymer pellets (available from The Dow Chemical Company as 5E16S Polypropylene
Resin, 35 MFR - "5E16S"), 7.5 parts polypropylene homopolymer pellets (available from
The Dow Chemical Company as DX5E30S Polypropylene Resin, 75 MFR - "DX5E30S"), 2 parts
maleic anhydride grafted polypropylene pellets (available from Crompton as POLYBOND™
3200), and 50 parts polypropylene and ethylene copolymer pellets (available from The
Dow Chemical Company as 7C54H Polypropylene Resin, 12 MFR - "7C54H") and shaken in
a plastic bag. This mixed pellet blend is placed in the feed hopper of a Toyo PLASTAR™
SI-90 plastic injection molding machine equipped with a mold containing twin drops
for a standard ASTM tensile-bar and a two inch diameter optical disk. Parts are molded
from this compound using a temperature profile of 395°F (202°C) closest to the hopper
to 385°F (196°C) by the nozzle. The mold temperature is 100°F, the hold time is 15
seconds, and the back pressure used is 250 pounds per square inch (psi). The parts
produced are off-white in color and homogeneous in appearance, with a smooth surface
and no visible accumulations of glass fiber.
[0181] Comparative Example 1
[0182] Two 100 mil sheets of an impact polypropylene copolymer (INSPIRE
TM D 114.00, a propylene-ethylene copolymer having approximately 8.5 weight percent
ethylene, available from The Dow Chemical Company) having a melt flow rate of 0.5
g/10 min (230°C/2.16kg) is prepared. A 10 inch by 10 inch glass fiber continuous filament
mat (available from Owens Coming under the designation M8643) having a basis weight
of 450 g/m
2 is placed between two layers of the 100 mil PP sheet. This sandwich structure is
then consolidated in a press at about 500 psi and 170°C for approximately 5 minutes.
[0184] An aqueous polyolefin dispersion comprises 80 percent by weight deionized water and
20 percent by weight solids. The solids comprise 2.35 weight percent long chain carboxylic
acid surfactant and 17.65 weight percent of a propylene-rich propylene and ethylene
copolymer (9 percent ethylene) having a density of 0.876 grams per cubic centimeter
(g/cc) and a melt flow rate (MFR) (under conditions of 230°C and an applied load of
2.16 kilograms) of 25 grams per 10 minutes (g/10 min.). The average particle size
of the dispersion is about 0.61 microns with a polydispersity of 1.31. The pH value
of the melt-kneaded aqueous dispersion is 11.6. The aqueous dispersion is then diluted
to a solids content of about 10 weight percent.
[0185] A 10 inch by 10 inch glass fiber continuous filament mat having a basis weight of
450 g/m
2 is then impregnated with the diluted dispersion by immersing the mat into the dispersion.
The impregnated mat is then removed from the dispersion and excess dispersion is allowed
to drip off. The wetted mat is then dried in a vertical position in a convection oven
maintained at 100°C for 5 minutes. A dried coating weight of approximately 30 g/m
2 is achieved.
[0186] In a separate operation, a 100 mil sheet of an impact polypropylene copolymer (INSPIRE
TM D 114.00, available from The Dow Chemical Company) having a melt flow rate of 0.5
g/10 min (230°C/2.16kg) is prepared. The impregnated mat is then placed between two
layers of the 100 mil PP sheet. This sandwich structure is then consolidated in a
press at about 500 psi and about 170°C for approximately 5 minutes. The resulting
glass reinforced thermoplastic structure may be used in various applications.
[0187] When compared to Comparative Example 1, the composite product of Example 6 exhibits
better mechanical properties, such as higher elongation to break, higher tensile strength,
and higher impact resistance.
[0189] An aqueous polyolefin dispersion based on a blend of an unfunctionalized PP (VERSIFY™
DP4200) and PRIMACOR
TM 5980I is prepared. VERSIFY™ DP4200 is a propylene-ethylene copolymer having an ethylene
content of about 9 weight percent and a melt flow of 25 dg/min (230°C, 2.16 kg). PRIMACOR™
is an ethylene-acrylic acid copolymer having an acrylic acid content of about 20.5
weight percent and a melt flow of approximately 13.75 dg/min (125°C, 2.16 kg). The
VERSIFY™ DP4200 / PRIMACOR
TM 59801 dispersion is produced by simultaneously feeding DP4200 pellets at 13.9 lb/hr
and 59801 pellets at 2.9 lb/hr into an extruder feed funnel. Deionized water and a
25% (w/w) aqueous solution of potassium hydroxide are pumped at 19 and 8.3 cc/min,
respectively, combined, heated to about 160°C, and injected into the extruder barrel
at the emulsification zone, where the barrels are operated at about 150°C. Deionized
water is pumped at 90 cc/min, heated to about 110°C, and injected into the extruder
barrel at the dilution section where the barrels are operated at about 80°C. Product
dilution is controlled at a pressure of about 300 psig. The resulting VERSIFY™ DP4200
/ PRIMACOR™ 5980I dispersion had a solids content of 51.6 weight percent, a pH of
about 10.0, a volume-mean particle size of about 1.0 micron as measured by a Beckman
Coulter LS 230, and a polydispersity (defined as the volume-mean particle size divided
by the number mean particle size) of less than 2.
[0190] The VERSIFY™ DP4200 / PRIMACOR™ 5980I dispersion is diluted to a solids content of
about 10 weight percent. A continuous glass roving strand (VETROTEX™ RO99 719 available
from Saint-Gobain) is unwound from the outside of a standard bobbin. The roving is
pulled through the aqueous thermoplastic dispersion by a Brabender film pull roll
unit at a rate of 8 feet per minute (ft/min.). After immersing into and exiting the
bath, excess liquid is removed from the coated strand by contact with a fluoropolymer
wiper. The wet strand is pulled into a forced air oven maintained at a temperature
of 180°C. Inside the oven, the strand is passed over a series of pulleys and guides
to provide a sufficient path length for a one minute residence time in the oven. In
the oven, the water is driven off and the propylene polymer softened and fused. The
dry coated strand emerges from the oven tacky due to the softened polymer coating
on the glass fibers. The coated strand quickly air cools to a stiff, flat bundle of
coated glass fibers.
[0191] In a separate operation, the coated bundle of glass fibers is subsequently woven
into a biaxial fabric using conventional weaving methods known to those skilled in
the art.
[0192] In a separate operation, a 100 mil sheet of an impact polypropylene copolymer (INSPIRE
TM D 114.00, available from The Dow Chemical Company) having a melt flow rate of 0.5
g/10 min (230°C/2.16kg) is prepared. The biaxial fabric is then placed between two
layers of the 100 mil PP sheet. This sandwich structure is then consolidated in a
press at about 500 psi and about 170°C for approximately 5 minutes. The resulting
glass reinforced thermoplastic structure may be used in various applications.
[0193] Compared to Comparative Example I, the composite product of Example 7 exhibits better
mechanical properties, such as higher elongation to break, higher tensile strength,
and higher impact resistance. This may be due to the presence of an unfunctionalized
polypropylene phase which may provide better compatibility with the impact polypropylene
copolymer sheets.
[0195] An aqueous polyolefin dispersion based on a blend of an unfunctionalized PP (VERSIFY™
DP4200) and PRlMACOR™ 59801 is prepared. The VERSIFY™ DP4200 / PRIMACOR
TM 59801 dispersion is produced by simultaneously feeding DP4200 pellets at 13.9 lb/hr
and 59801 pellets at 2.9 lb/hr into an extruder feed funnel. Deionized water and a
25% (w/w) aqueous solution of potassium hydroxide are pumped at 19 and 8.3 cc/min,
respectively, combined, heated to about 160°C, and injected into the extruder barrel
at the emulsification zone, where the barrels are operated at about 150°C. Deionized
water is pumped at 90 cc/min, heated to about 1 10°C, and injected into the extruder
barrel at the dilution section where the barrels are operated at about 80°C. Product
dilution is controlled at a pressure of about 300 psig. The resulting VERSIFY
TM DP4200 / PRIMACOR™ 5980I dispersion had a solids content of 51.6 weight percent,
a pH of about 10.0, a volume-mean particle size of about 1.0 micron as measured by
a Beckman Coulter LS 230, and a polydispersity (defined as the volume-mean particle
size divided by the number mean particle size) of less than 2. The VERSIFY™ DP4200
/ PRIMACOR™ 5980I dispersion is diluted to a solids content of about 10 weight percent.
[0196] A continuous glass roving strand is prepared using conventional glass manufacturing
methods know to those skilled in the art. Upon exiting the bushing for the glass manufacturing
operation, the fibers are pulled through the dilute VERSIFY™ DP4200 / PRIMACOR™ 5980I
dispersion. After immersing into and exiting the bath, excess liquid is removed from
the coated strand by contact with a fluoropolymer wiper. The wet strand is pulled
into a forced air oven maintained at a temperature of 180°C. Inside the oven, the
strand is passed over a series of pulleys and guides to provide a sufficient path
length for a one minute residence time in the oven. In the oven, the water is driven
off and the propylene polymer softened and fused. The dry coated strand emerges from
the oven tacky due to the softened polymer coating on the glass fibers. The coated
strand quickly air cools to a stiff, flat bundle of coated glass fibers.
[0197] In a separate operation, the coated bundle of glass fibers is subsequently woven
into a biaxial fabric using conventional weaving methods known to those skilled in
the art.
[0198] In a separate operation, a 100 mil sheet of an impact copolymer polypropylene (INSPIRE™
D 114.00, available from The Dow Chemical Company) having a melt flow rate of 0.5
g/10 min (230C/2.16kg) is prepared. The biaxial fabric is then placed between two
layers of the 100 mil PP sheet. This sandwich structure is then consolidated in a
press at about 500 psi and about 170°C for approximately 5 minutes. The resulting
glass reinforced thermoplastic structure may be used in various applications.
[0199] Advantageously, one or more embodiments disclosed herein may provide compositions,
methods, and articles having good performance in their intended applications. For
example, one or more embodiments may provide fibrous structures having one or more
of improved stiffness, elasticity, resilience, adhesion, shape retention or compatibility.
[0200] While the invention has been described with respect to a limited number of embodiments,
those skilled in the art, having benefit of this disclosure, will appreciate that
other embodiments can be devised which do not depart from the scope of the invention
as disclosed herein. Accordingly, the scope of the invention should be limited only
by the attached claims.
[0201] Features of the invention will now be described in the following numbered clauses
:
- 1. A method of forming an article, the method comprising:
applying a compound to a glass-containing substrate, the compound comprising:
an aqueous dispersion comprising:
- (a) a thermoplastic resin;
- (b) a dispersion stabilizing agent; and
- (c) water;
removing at least a portion of the water.
- 2. The method of clause 1, comprising removing at least 50% of the water.
- 3. The method of clause 1, wherein the article is at least 92 weight percent glass
based on a total weight of the substrate, the thermoplastic resin, and the dispersion
stabilizing agent.
- 4. The method of clause 1, wherein the article is at least 94 weight percent glass
based on a total weight of the substrate, the thermoplastic resin, and the dispersion
stabilizing agent.
- 5. The dispersion of clause 1, wherein the thermoplastic resin is non-polar and the
dispersion stabilizing agent is polar.
- 6. The method of clause 5, wherein the thermoplastic resin and dispersion stabilizing
agent form two distinct phases.
- 7. The method of clause 1 , wherein the removing at least a portion of the water results
in a coating having a thickness of between 0.1 microns and 100 microns.
- 8. The method of clause 1, wherein the removing at least a portion of the water results
in a coating weight of between 1 gram per square meter of substrate surface area and
100 grams per square meter of substrate surface area.
- 9. The method of clause 1, wherein the thermoplastic resin comprises a polyethylene
homopolymer, copolymer, or multiblock interpolymer, a polypropylene homopolymer, copolymer,
or multiblock interpolymer, or combinations thereof.
- 10. The method of clause 9, wherein the thermoplastic resin is non-polar.
- 11. The method of clause 1, wherein the thermoplastic resin has a heat deflection
temperature under load between 75°C and 110°C.
- 12. The method of clause 1, further comprising binding the article directly to a fabric
without an adhesive.
- 13. An article comprising:
a compound in contact with a portion of a glass-containing substrate, wherein the
compound at the time of contacting comprised an aqueous dispersion comprising:
- (a) a polyolefin having a deformation temperature of less than 110°C;
- (b) a dispersion stabilizing agent; and
- (c) water
wherein the compound imparts a modified property to the substrate; and wherein the
substrate is formable.
- 14. The article of clause 13, wherein a thermoforming temperature of the article is
within 50°C of a melting temperature of the polyolefin.
- 15. The article of clause 13, wherein the modified property is at least one selected
from the group consisting of adhesion to a second substrate, a tensile strength, a
compatibility, and an adhesive force.
- 16. The article of clause 15, wherein the modified property has a value at least 10%
greater than the uncontacted substrate.
- 17. The article of clause 15, wherein the adhesive force of the article is between
0.7 and 1.1 lb/in.
- 18. The article of clause 13, wherein the polyolefin comprises a polyethylene homopolymer,
copolymer, or multiblock interpolymer, a polypropylene homopolymer, copolymer, or
multiblock interpolymer, or combinations thereof.
- 19. The article of clause 18, wherein the polyolefin has a heat deflection temperature
under load between 75°C and 110°C.
- 20. The article of clause 13, wherein the glass-containing article has a basis weight
in the range from 25 to 1000 grams per square meter.
- 21. An article comprising:
a compound in contact with a portion of a glass-containing substrate, wherein the
compound at the time of contacting comprised an aqueous dispersion comprising:
- (a) a thermoplastic resin;
- (b) a dispersion stabilizing agent; and
- (c) water
wherein the article is at least 92 percent by weight glass based on a total weight
of the glass-containing substrate,
the thermoplastic resin, and the dispersion stabilizing agent.
- 22. The article of clause 21, wherein the article is at least 94 percent by weight
glass based on a total weight of the glass-containing substrate, the thermoplastic
resin, and the dispersion stabilizing agent,
- 23. The article of clause 21, wherein the article is selected from the group consisting
of mats, nonwovens, wovens, and fabrics.
- 24. The article of clause 21, wherein the glass is type E-glass.
- 25. A coated fiber, comprising:
a compound in contact with a portion of a glass-based fiber,
wherein the compound at the time of contacting comprised an aqueous dispersion comprising:
- (a) a thermoplastic resin;
- (b) a dispersion stabilizing agent; and
- (c) water
wherein the fiber has a diameter between 5 and 35 microns;
and wherein a thickness of a coating layer of the compound on the glass-based fiber
ranges from about 0.1 to 10 microns.
- 26. The coated fiber of clause 25, wherein the thermoplastic resin comprises a polyolefin
having a Vicat softening point between 75°C and 110°C.
- 27. The coated fiber of clause 25, wherein the thermoplastic resin comprises a polyethylene
homopolymer, copolymer, or multiblock interpolymer, a polypropylene homopolymer, copolymer,
or multiblock interpolymer, or combinations thereof.
- 28. The coated fiber of clause 27, wherein the thermoplastic resin is a non-functionalized
polymer.
- 29. An article formed from the coated fiber of clause 25.
- 30. A method of coating a fiber comprising:
applying a compound to a glass-based fiber, the compound comprising:
an aqueous dispersion comprising:
- (a) a thermoplastic resin;
- (b) a dispersion stabilizing agent; and
- (c) water;
removing at least a portion of the water.
- 31. The method of clause 30, wherein the applying comprises:
contacting a fiber strand with the aqueous dispersion; and
passing the fiber through a shaping device.
- 32. The method of clause 30, wherein the glass-based fiber is a comminuted glass-based
fiber.
- 33. The method of clause 30, wherein the glass-based fiber is a continuous fiber strand.
- 34. An article comprising:
at least one layer of a compound disposed on at least a portion of a glass-containing
substrate, wherein the compound comprises:
- (a) a polyolefin having a deformation temperature of less than 110°C; and
- (b) a dispersion stabilizing agent; and
wherein the compound imparts a modified property to the substrate; and wherein the
substrate is formable.
- 35. The article of clause 34, wherein the article is at least 92 weight percent glass
based on a total weight of the substrate, the thermoplastic resin, and the dispersion
stabilizing agent.
- 36. The article of clause 34, wherein the thermoplastic resin is non-functionalized
and the dispersion stabilizing agent is functionalized.
- 37. The article of clause 34, wherein the thermoplastic resin is non-polar and the
dispersion stabilizing agent is polar.
- 38. The article of clause 37, wherein the thermoplastic resin and dispersion stabilizing
agent form two distinct phases.
- 39. The article of clause 34, wherein the article has a melting temperature of less
than 110°C.